Sympa before 6.2.56 allows privilege escalation.
A vulnerability was found in all openshift/mediawiki-apb 4.x.x versions prior to 4.3.0, where an insecure modification vulnerability in the /etc/passwd file was found in the container openshift/mediawiki-apb. An attacker with access to the container could use this flaw to modify /etc/passwd and escalate their privileges.
An insecure modification vulnerability in the /etc/passwd file was found in the operator-framework/hadoop as shipped in Red Hat Openshift 4. An attacker with access to the container could use this flaw to modify /etc/passwd and escalate their privileges.
It was discovered that a systemd service that uses DynamicUser property can create a SUID/SGID binary that would be allowed to run as the transient service UID/GID even after the service is terminated. A local attacker may use this flaw to access resources that will be owned by a potentially different service in the future, when the UID/GID will be recycled.
The pg_ctlcluster script in postgresql-common in versions prior to 210 didn't drop privileges when creating socket/statistics temporary directories, which could result in local privilege escalation.
gksu-polkit-0.0.3-6.fc18 was reported as fixing the issue in CVE-2012-5617 but the patch was improperly applied and it did not fixed the security issue.
A flaw was found in the QEMU Guest Agent service for Windows. A local unprivileged user may be able to manipulate the QEMU Guest Agent's Windows installer via repair custom actions to elevate their privileges on the system.
NVIDIA GPU Display Driver for Windows contains a vulnerability in the kernel mode layer handler, where improper privilege management can lead to escalation of privileges and information disclosure.
multipath-tools 0.7.0 through 0.9.x before 0.9.2 allows local users to obtain root access, as exploited alone or in conjunction with CVE-2022-41973. Local users able to write to UNIX domain sockets can bypass access controls and manipulate the multipath setup. This can lead to local privilege escalation to root. This occurs because an attacker can repeat a keyword, which is mishandled because arithmetic ADD is used instead of bitwise OR.
NuGet Client Elevation of Privilege Vulnerability
A flaw was found in the way qemu v1.3.0 and later (virtio-rng) validates addresses when guest accesses the config space of a virtio device. If the virtio device has zero/small sized config space, such as virtio-rng, a privileged guest user could use this flaw to access the matching host's qemu address space and thus increase their privileges on the host.
An issue was discovered in Xen through 4.14.x. The PCI passthrough code improperly uses register data. Code paths in Xen's MSI handling have been identified that act on unsanitized values read back from device hardware registers. While devices strictly compliant with PCI specifications shouldn't be able to affect these registers, experience shows that it's very common for devices to have out-of-spec "backdoor" operations that can affect the result of these reads. A not fully trusted guest may be able to crash Xen, leading to a Denial of Service (DoS) for the entire system. Privilege escalation and information leaks cannot be excluded. All versions of Xen supporting PCI passthrough are affected. Only x86 systems are vulnerable. Arm systems are not vulnerable. Only guests with passed through PCI devices may be able to leverage the vulnerability. Only systems passing through devices with out-of-spec ("backdoor") functionality can cause issues. Experience shows that such out-of-spec functionality is common; unless you have reason to believe that your device does not have such functionality, it's better to assume that it does.
An issue was discovered in TrouSerS through 0.3.14. If the tcsd daemon is started with root privileges, the tss user still has read and write access to the /etc/tcsd.conf file (which contains various settings related to this daemon).
UC-8100A-ME-T System Image: Versions v1.0 to v1.6, UC-2100 System Image: Versions v1.0 to v1.12, UC-2100-W System Image: Versions v1.0 to v 1.12, UC-3100 System Image: Versions v1.0 to v1.6, UC-5100 System Image: Versions v1.0 to v1.4, UC-8100 System Image: Versions v3.0 to v3.5, UC-8100-ME-T System Image: Versions v3.0 and v3.1, UC-8200 System Image: v1.0 to v1.5, AIG-300 System Image: v1.0 to v1.4, UC-8410A with Debian 9 System Image: Versions v4.0.2 and v4.1.2, UC-8580 with Debian 9 System Image: Versions v2.0 and v2.1, UC-8540 with Debian 9 System Image: Versions v2.0 and v2.1, and DA-662C-16-LX (GLB) System Image: Versions v1.0.2 to v1.1.2 of Moxa's ARM-based computers have an execution with unnecessary privileges vulnerability, which could allow an attacker with user-level privileges to gain root privileges.
VMware Tools (12.0.0, 11.x.y and 10.x.y) contains a local privilege escalation vulnerability. A malicious actor with local non-administrative access to the Guest OS can escalate privileges as a root user in the virtual machine.
The inode_init_owner function in fs/inode.c in the Linux kernel through 3.16 allows local users to create files with an unintended group ownership, in a scenario where a directory is SGID to a certain group and is writable by a user who is not a member of that group. Here, the non-member can trigger creation of a plain file whose group ownership is that group. The intended behavior was that the non-member can trigger creation of a directory (but not a plain file) whose group ownership is that group. The non-member can escalate privileges by making the plain file executable and SGID.
net/netfilter/nf_dup_netdev.c in the Linux kernel 5.4 through 5.6.10 allows local users to gain privileges because of a heap out-of-bounds write. This is related to nf_tables_offload.
gksu-polkit: permissive PolicyKit policy configuration file allows privilege escalation
A Privilege Context Switching issue was discovered in join.c in Firejail 0.9.68. By crafting a bogus Firejail container that is accepted by the Firejail setuid-root program as a join target, a local attacker can enter an environment in which the Linux user namespace is still the initial user namespace, the NO_NEW_PRIVS prctl is not activated, and the entered mount namespace is under the attacker's control. In this way, the filesystem layout can be adjusted to gain root privileges through execution of available setuid-root binaries such as su or sudo.
In fuse before versions 2.9.8 and 3.x before 3.2.5, fusermount is vulnerable to a restriction bypass when SELinux is active. This allows non-root users to mount a FUSE file system with the 'allow_other' mount option regardless of whether 'user_allow_other' is set in the fuse configuration. An attacker may use this flaw to mount a FUSE file system, accessible by other users, and trick them into accessing files on that file system, possibly causing Denial of Service or other unspecified effects.
A flaw was found in the way Linux kernel KVM hypervisor before 4.18 emulated instructions such as sgdt/sidt/fxsave/fxrstor. It did not check current privilege(CPL) level while emulating unprivileged instructions. An unprivileged guest user/process could use this flaw to potentially escalate privileges inside guest.
The grc-policy-propagator allows security escalation within the cluster. The propagator allows policies which contain some dynamically obtained values (instead of the policy apply a static manifest on a managed cluster) of taking advantage of cluster scoped access in a created policy. This feature does not restrict properly to lookup content from the namespace where the policy was created.
mom creates world-writable pid files in /var/run
In Sudo before 1.9.12p2, the sudoedit (aka -e) feature mishandles extra arguments passed in the user-provided environment variables (SUDO_EDITOR, VISUAL, and EDITOR), allowing a local attacker to append arbitrary entries to the list of files to process. This can lead to privilege escalation. Affected versions are 1.8.0 through 1.9.12.p1. The problem exists because a user-specified editor may contain a "--" argument that defeats a protection mechanism, e.g., an EDITOR='vim -- /path/to/extra/file' value.
systemd before 247 does not adequately block local privilege escalation for some Sudo configurations, e.g., plausible sudoers files in which the "systemctl status" command may be executed. Specifically, systemd does not set LESSSECURE to 1, and thus other programs may be launched from the less program. This presents a substantial security risk when running systemctl from Sudo, because less executes as root when the terminal size is too small to show the complete systemctl output.
IPython (Interactive Python) is a command shell for interactive computing in multiple programming languages, originally developed for the Python programming language. Affected versions are subject to an arbitrary code execution vulnerability achieved by not properly managing cross user temporary files. This vulnerability allows one user to run code as another on the same machine. All users are advised to upgrade.
A Privilege Escalation vulnerability exits in Fedoraproject Sectool due to an incorrect DBus file.
In the Linux kernel, the following vulnerability has been resolved: ptrace: slightly saner 'get_dumpable()' logic The 'dumpability' of a task is fundamentally about the memory image of the task - the concept comes from whether it can core dump or not - and makes no sense when you don't have an associated mm. And almost all users do in fact use it only for the case where the task has a mm pointer. But we have one odd special case: ptrace_may_access() uses 'dumpable' to check various other things entirely independently of the MM (typically explicitly using flags like PTRACE_MODE_READ_FSCREDS). Including for threads that no longer have a VM (and maybe never did, like most kernel threads). It's not what this flag was designed for, but it is what it is. The ptrace code does check that the uid/gid matches, so you do have to be uid-0 to see kernel thread details, but this means that the traditional "drop capabilities" model doesn't make any difference for this all. Make it all make a *bit* more sense by saying that if you don't have a MM pointer, we'll use a cached "last dumpability" flag if the thread ever had a MM (it will be zero for kernel threads since it is never set), and require a proper CAP_SYS_PTRACE capability to override.
arch/x86/kernel/entry_64.S in the Linux kernel before 3.17.5 does not properly handle faults associated with the Stack Segment (SS) segment register, which allows local users to gain privileges by triggering an IRET instruction that leads to access to a GS Base address from the wrong space.
An Elevated Privileges issue exists in JBoss AS 7 Community Release due to the improper implementation in the security context propagation, A threat gets reused from the thread pool that still retains the security context from the process last used, which lets a local user obtain elevated privileges.
PCI devices with RMRRs not deassigned correctly Certain PCI devices in a system might be assigned Reserved Memory Regions (specified via Reserved Memory Region Reporting, "RMRR"). These are typically used for platform tasks such as legacy USB emulation. If such a device is passed through to a guest, then on guest shutdown the device is not properly deassigned. The IOMMU configuration for these devices which are not properly deassigned ends up pointing to a freed data structure, including the IO Pagetables. Subsequent DMA or interrupts from the device will have unpredictable behaviour, ranging from IOMMU faults to memory corruption.
The Debian shadow package before 1:4.5-1 for Shadow incorrectly lists pts/0 and pts/1 as physical terminals in /etc/securetty. This allows local users to login as password-less users even if they are connected by non-physical means such as SSH (hence bypassing PAM's nullok_secure configuration). This notably affects environments such as virtual machines automatically generated with a default blank root password, allowing all local users to escalate privileges.
The do_change_type function in fs/namespace.c in the Linux kernel before 2.6.22 does not verify that the caller has the CAP_SYS_ADMIN capability, which allows local users to gain privileges or cause a denial of service by modifying the properties of a mountpoint.
Bubblewrap (bwrap) before version 0.4.1, if installed in setuid mode and the kernel supports unprivileged user namespaces, then the `bwrap --userns2` option can be used to make the setuid process keep running as root while being traceable. This can in turn be used to gain root permissions. Note that this only affects the combination of bubblewrap in setuid mode (which is typically used when unprivileged user namespaces are not supported) and the support of unprivileged user namespaces. Known to be affected are: * Debian testing/unstable, if unprivileged user namespaces enabled (not default) * Debian buster-backports, if unprivileged user namespaces enabled (not default) * Arch if using `linux-hardened`, if unprivileged user namespaces enabled (not default) * Centos 7 flatpak COPR, if unprivileged user namespaces enabled (not default) This has been fixed in the 0.4.1 release, and all affected users should update.
An issue was discovered in Xen through 4.14.x. Access rights of Xenstore nodes are per domid. Unfortunately, existing granted access rights are not removed when a domain is being destroyed. This means that a new domain created with the same domid will inherit the access rights to Xenstore nodes from the previous domain(s) with the same domid. Because all Xenstore entries of a guest below /local/domain/<domid> are being deleted by Xen tools when a guest is destroyed, only Xenstore entries of other guests still running are affected. For example, a newly created guest domain might be able to read sensitive information that had belonged to a previously existing guest domain. Both Xenstore implementations (C and Ocaml) are vulnerable.
An issue was discovered in TrouSerS through 0.3.14. If the tcsd daemon is started with root privileges instead of by the tss user, it fails to drop the root gid privilege when no longer needed.
Jann Horn of Google Project Zero discovered that NTFS-3G, a read-write NTFS driver for FUSE, does not scrub the environment before executing modprobe with elevated privileges. A local user can take advantage of this flaw for local root privilege escalation.
Sympa through 6.2.57b.2 allows a local privilege escalation from the sympa user account to full root access by modifying the sympa.conf configuration file (which is owned by sympa) and parsing it through the setuid sympa_newaliases-wrapper executable.
mount.ecryptfs_private.c in eCryptfs-utils does not validate mount destination filesystem types, which allows local users to gain privileges by mounting over a nonstandard filesystem, as demonstrated by /proc/$pid.
An issue was found in Linux kernel before 5.5.4. The mwifiex_cmd_append_vsie_tlv() function in drivers/net/wireless/marvell/mwifiex/scan.c allows local users to gain privileges or cause a denial of service because of an incorrect memcpy and buffer overflow, aka CID-b70261a288ea.
In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: check/clear fast rx for non-4addr sta VLAN changes When moving a station out of a VLAN and deleting the VLAN afterwards, the fast_rx entry still holds a pointer to the VLAN's netdev, which can cause use-after-free bugs. Fix this by immediately calling ieee80211_check_fast_rx after the VLAN change.
In the Linux kernel, the following vulnerability has been resolved: af_unix: Don't leave consecutive consumed OOB skbs. Jann Horn reported a use-after-free in unix_stream_read_generic(). The following sequences reproduce the issue: $ python3 from socket import * s1, s2 = socketpair(AF_UNIX, SOCK_STREAM) s1.send(b'x', MSG_OOB) s2.recv(1, MSG_OOB) # leave a consumed OOB skb s1.send(b'y', MSG_OOB) s2.recv(1, MSG_OOB) # leave a consumed OOB skb s1.send(b'z', MSG_OOB) s2.recv(1) # recv 'z' illegally s2.recv(1, MSG_OOB) # access 'z' skb (use-after-free) Even though a user reads OOB data, the skb holding the data stays on the recv queue to mark the OOB boundary and break the next recv(). After the last send() in the scenario above, the sk2's recv queue has 2 leading consumed OOB skbs and 1 real OOB skb. Then, the following happens during the next recv() without MSG_OOB 1. unix_stream_read_generic() peeks the first consumed OOB skb 2. manage_oob() returns the next consumed OOB skb 3. unix_stream_read_generic() fetches the next not-yet-consumed OOB skb 4. unix_stream_read_generic() reads and frees the OOB skb , and the last recv(MSG_OOB) triggers KASAN splat. The 3. above occurs because of the SO_PEEK_OFF code, which does not expect unix_skb_len(skb) to be 0, but this is true for such consumed OOB skbs. while (skip >= unix_skb_len(skb)) { skip -= unix_skb_len(skb); skb = skb_peek_next(skb, &sk->sk_receive_queue); ... } In addition to this use-after-free, there is another issue that ioctl(SIOCATMARK) does not function properly with consecutive consumed OOB skbs. So, nothing good comes out of such a situation. Instead of complicating manage_oob(), ioctl() handling, and the next ECONNRESET fix by introducing a loop for consecutive consumed OOB skbs, let's not leave such consecutive OOB unnecessarily. Now, while receiving an OOB skb in unix_stream_recv_urg(), if its previous skb is a consumed OOB skb, it is freed. [0]: BUG: KASAN: slab-use-after-free in unix_stream_read_actor (net/unix/af_unix.c:3027) Read of size 4 at addr ffff888106ef2904 by task python3/315 CPU: 2 UID: 0 PID: 315 Comm: python3 Not tainted 6.16.0-rc1-00407-gec315832f6f9 #8 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-4.fc42 04/01/2014 Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:122) print_report (mm/kasan/report.c:409 mm/kasan/report.c:521) kasan_report (mm/kasan/report.c:636) unix_stream_read_actor (net/unix/af_unix.c:3027) unix_stream_read_generic (net/unix/af_unix.c:2708 net/unix/af_unix.c:2847) unix_stream_recvmsg (net/unix/af_unix.c:3048) sock_recvmsg (net/socket.c:1063 (discriminator 20) net/socket.c:1085 (discriminator 20)) __sys_recvfrom (net/socket.c:2278) __x64_sys_recvfrom (net/socket.c:2291 (discriminator 1) net/socket.c:2287 (discriminator 1) net/socket.c:2287 (discriminator 1)) do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) RIP: 0033:0x7f8911fcea06 Code: 5d e8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 75 19 83 e2 39 83 fa 08 75 11 e8 26 ff ff ff 66 0f 1f 44 00 00 48 8b 45 10 0f 05 <48> 8b 5d f8 c9 c3 0f 1f 40 00 f3 0f 1e fa 55 48 89 e5 48 83 ec 08 RSP: 002b:00007fffdb0dccb0 EFLAGS: 00000202 ORIG_RAX: 000000000000002d RAX: ffffffffffffffda RBX: 00007fffdb0dcdc8 RCX: 00007f8911fcea06 RDX: 0000000000000001 RSI: 00007f8911a5e060 RDI: 0000000000000006 RBP: 00007fffdb0dccd0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000202 R12: 00007f89119a7d20 R13: ffffffffc4653600 R14: 0000000000000000 R15: 0000000000000000 </TASK> Allocated by task 315: kasan_save_stack (mm/kasan/common.c:48) kasan_save_track (mm/kasan/common.c:60 (discriminator 1) mm/kasan/common.c:69 (discriminator 1)) __kasan_slab_alloc (mm/kasan/common.c:348) kmem_cache_alloc_ ---truncated---
In the Linux kernel, the following vulnerability has been resolved: bpf: Protect against int overflow for stack access size This patch re-introduces protection against the size of access to stack memory being negative; the access size can appear negative as a result of overflowing its signed int representation. This should not actually happen, as there are other protections along the way, but we should protect against it anyway. One code path was missing such protections (fixed in the previous patch in the series), causing out-of-bounds array accesses in check_stack_range_initialized(). This patch causes the verification of a program with such a non-sensical access size to fail. This check used to exist in a more indirect way, but was inadvertendly removed in a833a17aeac7.
In the Linux kernel, the following vulnerability has been resolved: drm/i915/gt: Fix timeline left held on VMA alloc error The following error has been reported sporadically by CI when a test unbinds the i915 driver on a ring submission platform: <4> [239.330153] ------------[ cut here ]------------ <4> [239.330166] i915 0000:00:02.0: [drm] drm_WARN_ON(dev_priv->mm.shrink_count) <4> [239.330196] WARNING: CPU: 1 PID: 18570 at drivers/gpu/drm/i915/i915_gem.c:1309 i915_gem_cleanup_early+0x13e/0x150 [i915] ... <4> [239.330640] RIP: 0010:i915_gem_cleanup_early+0x13e/0x150 [i915] ... <4> [239.330942] Call Trace: <4> [239.330944] <TASK> <4> [239.330949] i915_driver_late_release+0x2b/0xa0 [i915] <4> [239.331202] i915_driver_release+0x86/0xa0 [i915] <4> [239.331482] devm_drm_dev_init_release+0x61/0x90 <4> [239.331494] devm_action_release+0x15/0x30 <4> [239.331504] release_nodes+0x3d/0x120 <4> [239.331517] devres_release_all+0x96/0xd0 <4> [239.331533] device_unbind_cleanup+0x12/0x80 <4> [239.331543] device_release_driver_internal+0x23a/0x280 <4> [239.331550] ? bus_find_device+0xa5/0xe0 <4> [239.331563] device_driver_detach+0x14/0x20 ... <4> [357.719679] ---[ end trace 0000000000000000 ]--- If the test also unloads the i915 module then that's followed with: <3> [357.787478] ============================================================================= <3> [357.788006] BUG i915_vma (Tainted: G U W N ): Objects remaining on __kmem_cache_shutdown() <3> [357.788031] ----------------------------------------------------------------------------- <3> [357.788204] Object 0xffff888109e7f480 @offset=29824 <3> [357.788670] Allocated in i915_vma_instance+0xee/0xc10 [i915] age=292729 cpu=4 pid=2244 <4> [357.788994] i915_vma_instance+0xee/0xc10 [i915] <4> [357.789290] init_status_page+0x7b/0x420 [i915] <4> [357.789532] intel_engines_init+0x1d8/0x980 [i915] <4> [357.789772] intel_gt_init+0x175/0x450 [i915] <4> [357.790014] i915_gem_init+0x113/0x340 [i915] <4> [357.790281] i915_driver_probe+0x847/0xed0 [i915] <4> [357.790504] i915_pci_probe+0xe6/0x220 [i915] ... Closer analysis of CI results history has revealed a dependency of the error on a few IGT tests, namely: - igt@api_intel_allocator@fork-simple-stress-signal, - igt@api_intel_allocator@two-level-inception-interruptible, - igt@gem_linear_blits@interruptible, - igt@prime_mmap_coherency@ioctl-errors, which invisibly trigger the issue, then exhibited with first driver unbind attempt. All of the above tests perform actions which are actively interrupted with signals. Further debugging has allowed to narrow that scope down to DRM_IOCTL_I915_GEM_EXECBUFFER2, and ring_context_alloc(), specific to ring submission, in particular. If successful then that function, or its execlists or GuC submission equivalent, is supposed to be called only once per GEM context engine, followed by raise of a flag that prevents the function from being called again. The function is expected to unwind its internal errors itself, so it may be safely called once more after it returns an error. In case of ring submission, the function first gets a reference to the engine's legacy timeline and then allocates a VMA. If the VMA allocation fails, e.g. when i915_vma_instance() called from inside is interrupted with a signal, then ring_context_alloc() fails, leaving the timeline held referenced. On next I915_GEM_EXECBUFFER2 IOCTL, another reference to the timeline is got, and only that last one is put on successful completion. As a consequence, the legacy timeline, with its underlying engine status page's VMA object, is still held and not released on driver unbind. Get the legacy timeline only after successful allocation of the context engine's VMA. v2: Add a note on other submission methods (Krzysztof Karas): Both execlists and GuC submission use lrc_alloc() which seems free from a similar issue. (cherry picked from commit cc43422b3cc79eacff4c5a8ba0d224688ca9dd4f)
In the Linux kernel, the following vulnerability has been resolved: irqchip/gic-v3-its: Prevent double free on error The error handling path in its_vpe_irq_domain_alloc() causes a double free when its_vpe_init() fails after successfully allocating at least one interrupt. This happens because its_vpe_irq_domain_free() frees the interrupts along with the area bitmap and the vprop_page and its_vpe_irq_domain_alloc() subsequently frees the area bitmap and the vprop_page again. Fix this by unconditionally invoking its_vpe_irq_domain_free() which handles all cases correctly and by removing the bitmap/vprop_page freeing from its_vpe_irq_domain_alloc(). [ tglx: Massaged change log ]
In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Flush pages under kvm->lock to fix UAF in svm_register_enc_region() Do the cache flush of converted pages in svm_register_enc_region() before dropping kvm->lock to fix use-after-free issues where region and/or its array of pages could be freed by a different task, e.g. if userspace has __unregister_enc_region_locked() already queued up for the region. Note, the "obvious" alternative of using local variables doesn't fully resolve the bug, as region->pages is also dynamically allocated. I.e. the region structure itself would be fine, but region->pages could be freed. Flushing multiple pages under kvm->lock is unfortunate, but the entire flow is a rare slow path, and the manual flush is only needed on CPUs that lack coherency for encrypted memory.
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix potential UAF in cifs_stats_proc_show() Skip sessions that are being teared down (status == SES_EXITING) to avoid UAF.
A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. A mismatch between the X server and the libXfont2 library's maximum font name length can cause a stack buffer overflow during font alias resolution. The server allocates a 256 byte stack buffer but libXfont2's alias target name length is 1024 bytes. A font alias name between 257 and 1023 bytes causes the X server to copy that name into the undersized stack buffer without further checks. This may be used to crash the server, or for privilege escalation if the X server runs as root.
A use-after-free flaw was found in the X.Org X server and Xwayland in miSyncDestroyFence(). A client that sets up multiple fence triggers can trigger a use-after-free function pointer call. An attacker would connect to the X server to set up a fence and await that fence, then a second X connection destroys the fence, causing the use-after-free. This may be used to crash the server, or for privilege escalation if the X server runs as root.
A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. The X server has multiple stack buffers sized XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify or clamp non-canonical key types to XkbMaxShiftLevel. A client can change key types to excessive shift levels and trigger stack overflows. This is caused by an incomplete fix of CVE-2025-26597. This may be used to crash the server, or for privilege escalation if the X server runs as root.