FreeRDP before 3.29.0 (affected versions <= 3.28.0) contains a heap out-of-bounds read in update_process_glyph_fragments()/glyph_cache_fragment_put() in libfreerdp/cache/glyph.c. When handling a GLYPH_FRAGMENT_ADD update, the code reads a one-byte server-controlled declared fragment size but does not verify it fits within the remaining received buffer before allocating and copying that many bytes. A malicious RDP server can send a short fragment with an oversized declared size, causing the client to read beyond the allocated buffer, resulting in an out-of-bounds read and client crash.

FreeRDP before 3.29.0 contains out-of-bounds read vulnerabilities in the async update message proxy for the PolygonSC and PolygonCB primary drawing orders. When AsyncUpdate is enabled (e.g., xfreerdp /async-update), update_message_PolygonSC() and update_message_PolygonCB() allocate a fresh points array but copy point data from the address of the order structure instead of from polygonSC->points / polygonCB->points, resulting in a client-side out-of-bounds read. A malicious or compromised RDP server sending crafted PolygonSC/PolygonCB update orders can trigger memory disclosure or a client crash.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, `xf_rail_server_execute_result` indexes the global `error_code_names[]` array (7 elements, indices 0–6) with an unchecked `execResult->execResult` value received from the server, allowing an out-of-bounds read when the server sends an `execResult` value of 7 or greater. Version 3.23.0 fixes the issue.

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. Affected versions are subject to an Out-Of-Bounds Read in the `RleDecompress` function. This Out-Of-Bounds Read occurs because FreeRDP processes the `pbSrcBuffer` variable without checking if it contains data of sufficient length. Insufficient data in the `pbSrcBuffer` variable may cause errors or crashes. This issue has been addressed in version 3.0.0-beta3. Users are advised to upgrade. There are no known workarounds for this issue.

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. Affected versions are subject to an Out-Of-Bounds Read in the `nsc_rle_decompress_data` function. The Out-Of-Bounds Read occurs because it processes `context->Planes` without checking if it contains data of sufficient length. Should an attacker be able to leverage this vulnerability they may be able to cause a crash. This issue has been addressed in versions 2.11.0 and 3.0.0-beta3. Users are advised to upgrade. There are no known workarounds for this vulnerability.

FreeRDP before 3.30.0 (<= 3.29.0) contains a heap-based buffer overflow in the Windows clipboard client's CliprdrStream_Read function (client/Windows/wf_cliprdr.c). When an OLE paste consumer (e.g. explorer.exe) calls IStream::Read with a fixed-size buffer of cb bytes, CliprdrStream_Read requests file contents from the RDP server and then copies the response into the caller's buffer using the server-supplied length (req_fsize) instead of cb. A malicious or compromised RDP server can return an oversized CB_FILECONTENTS_RESPONSE, causing an out-of-bounds write of attacker-controlled data into the paste consumer's heap buffer when a user pastes server-offered clipboard file contents.

FreeRDP before 3.29.0 contains a null pointer dereference vulnerability in smartcard cache request decoders that accept NULL NDR pointers for LookupName in SCARD_IOCTL_READCACHEA and SCARD_IOCTL_WRITECACHEA operations. When smartcard emulation is enabled, attackers can send crafted smartcard cache requests with NULL lookup-name pointers to trigger strlen() on a null pointer, causing client process termination.

FreeRDP before 3.29.0 contains a denial of service vulnerability in the RDPEI server channel handler that fails to validate maximum PDU body length before stream allocation. A malicious RDP client can send a header-only RDPEI message with a large declared body length to force excessive memory allocation on the server.

FreeRDP before 3.29.0 fails to enforce the RESPONSE_SIZE_LIMIT when processing Transfer-Encoding: chunked HTTP responses in http_response_recv_body(). Attackers controlling a malicious RD Gateway endpoint can send oversized chunked response bodies to exhaust client memory resources without triggering the configured size limit.

FreeRDP versions 3.28.0 and earlier contain a heap buffer overflow in the server-side RAIL channel handler (rail_server_handle_messages() in channels/rail/server/rail_main.c). When processing a RAIL PDU header, the code subtracts RAIL_PDU_HEADER_LENGTH from the peer-controlled orderLength field without first verifying orderLength is at least the header length. For orderLength values 0..3 this causes an unsigned integer underflow to a very large size, which bypasses the Stream_EnsureRemainingCapacity() capacity check (due to pointer arithmetic wraparound) and is then passed to WTSVirtualChannelRead(), resulting in an out-of-bounds heap write. A malicious or compromised RDP client can exploit this to corrupt the heap and crash the server. Fixed in FreeRDP 3.29.0.

FreeRDP before 3.29.0 contains a client-side heap use-after-free in the async update message proxy for WINDOW_ICON_ORDER when AsyncUpdate is enabled (e.g. xfreerdp /async-update). In update_message_WindowIcon() a shallow CopyMemory() overwrites a freshly allocated lParam->iconInfo with the parser-owned windowIcon->iconInfo pointer. After the parser callback returns, update_recv_window_info_order() frees window_icon.iconInfo, but the queued async message still retains and later dispatches that stale pointer. A malicious or compromised RDP server sending a crafted RAIL Window Alternate Secondary Order with WINDOW_ORDER_ICON can trigger use-after-free, leading to memory corruption and client crash.

FreeRDP before 3.29.0 contains client-side heap use-after-free vulnerabilities in the async update message proxy for RAIL WINDOW_STATE_ORDER and NOTIFY_ICON_STATE_ORDER when AsyncUpdate is enabled. When a malicious or compromised RDP server sends crafted update orders, the message proxy shallow-copies structures containing nested parser-owned pointers (e.g., titleInfo.string, windowRects, visibilityRects, icon buffers). The parser frees those nested buffers after the callback returns, so the queued async message later dispatches stale pointers, potentially causing memory corruption or a client crash.

FreeRDP before 3.29.0 contains a null pointer dereference vulnerability in smartcard device control request cleanup when reader-state decoding fails. Attackers can send malformed smartcard IRP requests with non-zero cReaders and truncated reader-state data to crash the process via null pointer access in free_reader_states functions.

In FreeRDP before version 2.1.2, there is a use-after-free in gdi_SelectObject. All FreeRDP clients using compatibility mode with /relax-order-checks are affected. This is fixed in version 2.1.2.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.5.1, a malicious server can crash the FreeRDP client by sending invalid huge allocation size. Version 3.5.1 contains a patch for the issue. No known workarounds are available.

FreeRDP is a free implementation of the Remote Desktop Protocol. FreeRDP based clients prior to version 3.5.1 are vulnerable to a possible `NULL` access and crash. Version 3.5.1 contains a patch for the issue. No known workarounds are available.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, division by zero in MS-ADPCM and IMA-ADPCM decoders when nBlockAlign is 0, leading to a crash. In libfreerdp/codec/dsp.c, both ADPCM decoders use size % block_size where block_size = context->common.format.nBlockAlign. The nBlockAlign value comes from the Server Audio Formats PDU on the RDPSND channel. The value 0 is not validated anywhere before reaching the decoder. When nBlockAlign = 0, the modulo operation causes a SIGFPE (floating point exception) crash. This vulnerability is fixed in 3.24.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, `xf_rail_server_local_move_size` dereferences a freed `xfAppWindow` pointer because `xf_rail_get_window` returns an unprotected pointer from the `railWindows` hash table, and the main thread can concurrently delete the window (via a window delete order) while the RAIL channel thread is still using the pointer. Version 3.23.0 fixes the issue.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, `rail_window_free` dereferences a freed `xfAppWindow` pointer during `HashTable_Free` cleanup because `xf_rail_window_common` calls `free(appWindow)` on title allocation failure without first removing the entry from the `railWindows` hash table, leaving a dangling pointer that is freed again on disconnect. Version 3.23.0 fixes the vulnerability.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, ecam_encoder_compress_h264 trusts server-controlled dimensions and does not validate the source buffer size, leading to an out-of-bounds read in sws_scale. This vulnerability is fixed in 3.22.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, A capture thread sends sample responses using a freed channel callback after a device channel close, leading to a use after free in ecam_channel_write. This vulnerability is fixed in 3.22.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, urb_select_interface can free the device's MS config on error but later code still dereferences it, leading to a use after free in libusb_udev_select_interface. This vulnerability is fixed in 3.22.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, The URBDRC client uses server-supplied interface numbers as array indices without bounds checks, causing an out-of-bounds read in libusb_udev_select_interface. This vulnerability is fixed in 3.22.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, aAsynchronous bulk transfer completions can use a freed channel callback after URBDRC channel close, leading to a use after free in urb_write_completion. This vulnerability is fixed in 3.22.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, the RDPSND async playback thread can process queued PDUs after the channel is closed and internal state is freed, leading to a use after free in rdpsnd_treat_wave. This vulnerability is fixed in 3.22.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, AUDIN format renegotiation frees the active format list while the capture thread continues using audin->format, leading to a use after free in audio_format_compatible. This vulnerability is fixed in 3.22.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, audin_server_recv_formats frees an incorrect number of audio formats on parse failure (i + i), leading to out-of-bounds access in audio_formats_free. This vulnerability is fixed in 3.22.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. ainput_send_input_event caches channel_callback in a local variable and later uses it without synchronization; a concurrent channel close can free or reinitialize the callback, leading to a use after free. Prior to 3.22.0, This vulnerability is fixed in 3.22.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, FastGlyph parsing trusts `cbData`/remaining length and never validates against the minimum size implied by `cx/cy`. A malicious server can trigger a client‑side global buffer overflow, causing a crash (DoS). Version 3.21.0 contains a patch for the issue.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, video_timer can send client notifications after the control channel is closed, dereferencing a freed callback and triggering a use after free. This vulnerability is fixed in 3.22.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, progressive_decompress_tile_upgrade() detects a mismatch via progressive_rfx_quant_cmp_equal() but only emits WLog_WARN, execution continues. The wrapped value (247) is used as a shift exponent, causing undefined behavior and an approximately 80 billion iteration loop (CPU DoS). This issue has been patched in version 3.24.2.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, the function `Stream_EnsureCapacity` can create an endless blocking loop. This may affect all client and server implementations using `FreeRDP`. For practical exploitation this will only work on 32bit systems where the available physical memory is `>= SIZE_MAX`. Version 3.23.0 contains a patch. No known workarounds are available.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, the fix for the heap-use-after-free described in CVE-2026-24680 is incomplete. While the vulnerable execution flow referenced in the advisory exists in the SDL2 implementation, the fix appears to have been applied only to the SDL3 code path. In the SDL2 implementation, the pointer is not nulled after free. This creates a situation where the advisory suggests the vulnerability is fully resolved, while builds or environments still using SDL2 may retain the vulnerable logic. A complete fix is available in version 3.23.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, sdl_Pointer_New frees data on failure, then pointer_free calls sdl_Pointer_Free and frees it again, triggering ASan UAF. This vulnerability is fixed in 3.22.0.

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. In affected versions there is a Global-Buffer-Overflow in the ncrush_decompress function. Feeding crafted input into this function can trigger the overflow which has only been shown to cause a crash. This issue has been addressed in versions 2.11.0 and 3.0.0-beta3. Users are advised to upgrade. There are no known workarounds for this issue.

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. This issue affects Clients only. Integer underflow leading to DOS (e.g. abort due to `WINPR_ASSERT` with default compilation flags). When an insufficient blockLen is provided, and proper length validation is not performed, an Integer Underflow occurs, leading to a Denial of Service (DOS) vulnerability. This issue has been addressed in versions 2.11.0 and 3.0.0-beta3. Users are advised to upgrade. There are no known workarounds for this vulnerability.

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. Affected versions of FreeRDP are subject to a Null Pointer Dereference leading a crash in the RemoteFX (rfx) handling. Inside the `rfx_process_message_tileset` function, the program allocates tiles using `rfx_allocate_tiles` for the number of numTiles. If the initialization process of tiles is not completed for various reasons, tiles will have a NULL pointer. Which may be accessed in further processing and would cause a program crash. This issue has been addressed in versions 2.11.0 and 3.0.0-beta3. Users are advised to upgrade. There are no known workarounds for this vulnerability.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, a NULL pointer dereference vulnerability in rdp_write_logon_info_v2() allows a malicious RDP server to crash FreeRDP proxy by sending a specially crafted LogonInfoV2 PDU with cbDomain=0 or cbUserName=0. This vulnerability is fixed in 3.22.0.

FreeRDP before 3.29.0 contains an out-of-bounds heap read vulnerability in the UVC H.264 extension-unit parser that fails to validate descriptor length before accessing the GUID field. A local attacker with a malicious USB video camera can trigger a heap read beyond allocated bounds during camera stream setup, causing denial of service.

FreeRDP versions 3.28.0 and earlier contain an out-of-bounds read vulnerability in the RDP6 planar RLE bitmap decoder functions planar_decompress_plane_rle and planar_decompress_plane_rle_only in libfreerdp/codec/planar.c. Only the 1-byte control byte is bounds-checked; the subsequent 0–15 attacker-declared raw bytes are read without validating that the source buffer contains them. A malicious or compromised RDP server can send a truncated planar-encoded bitmap or surface update (reachable via both the Bitmap Update PDU and RDPGFX Surface Command paths) that causes the client to read past the end of the source buffer. The issue is fixed in FreeRDP 3.29.0.

In FreeRDP after 1.1 and before 2.0.0, there is an out-of-bound read of client memory that is then passed on to the protocol parser. This has been patched in 2.0.0.

In FreeRDP less than or equal to 2.0.0, there is an out-of-bound read in ntlm_read_AuthenticateMessage. This has been fixed in 2.1.0.

In FreeRDP before version 2.1.2, an out of bound reads occurs resulting in accessing a memory location that is outside of the boundaries of the static array PRIMARY_DRAWING_ORDER_FIELD_BYTES. This is fixed in version 2.1.2.

In FreeRDP less than or equal to 2.0.0, there is an out-of-bound read in ntlm_read_NegotiateMessage. This has been fixed in 2.1.0.

In FreeRDP less than or equal to 2.0.0, there is an out-of-bound data read from memory in clear_decompress_subcode_rlex, visualized on screen as color. This has been patched in 2.1.0.

In FreeRDP before 2.1.0, there is an out-of-bounds read in cliprdr_read_format_list. Clipboard format data read (by client or server) might read data out-of-bounds. This has been fixed in 2.1.0.

In FreeRDP less than or equal to 2.0.0, a possible resource exhaustion vulnerability can be performed. Malicious clients could trigger out of bound reads causing memory allocation with random size. This has been fixed in 2.1.0.

In FreeRDP less than or equal to 2.0.0, when running with logger set to "WLOG_TRACE", a possible crash of application could occur due to a read of an invalid array index. Data could be printed as string to local terminal. This has been fixed in 2.1.0.

In FreeRDP after 1.0 and before 2.0.0, there is an out-of-bound read in in update_read_bitmap_data that allows client memory to be read to an image buffer. The result displayed on screen as colour.

In FreeRDP after 1.0 and before 2.0.0, there is an out-of-bounds read. It only allows to abort a session. No data extraction is possible. This has been fixed in 2.0.0.