libcurl provides the `CURLOPT_CERTINFO` option to allow applications torequest details to be returned about a server's certificate chain.Due to an erroneous function, a malicious server could make libcurl built withNSS get stuck in a never-ending busy-loop when trying to retrieve thatinformation.

Due to a mistake in libcurl's WebSocket code, a malicious server can send a particularly crafted packet which makes libcurl get trapped in an endless busy-loop. There is no other way for the application to escape or exit this loop other than killing the thread/process. This might be used to DoS libcurl-using application.

libcurl versions from 7.36.0 to before 7.64.0 is vulnerable to a heap buffer out-of-bounds read. The function handling incoming NTLM type-2 messages (`lib/vauth/ntlm.c:ntlm_decode_type2_target`) does not validate incoming data correctly and is subject to an integer overflow vulnerability. Using that overflow, a malicious or broken NTLM server could trick libcurl to accept a bad length + offset combination that would lead to a buffer read out-of-bounds.

1. A cookie is set using the `secure` keyword for `https://target` 2. curl is redirected to or otherwise made to speak with `http://target` (same hostname, but using clear text HTTP) using the same cookie set 3. The same cookie name is set - but with just a slash as path (`path=\"/\",`). Since this site is not secure, the cookie *should* just be ignored. 4. A bug in the path comparison logic makes curl read outside a heap buffer boundary The bug either causes a crash or it potentially makes the comparison come to the wrong conclusion and lets the clear-text site override the contents of the secure cookie, contrary to expectations and depending on the memory contents immediately following the single-byte allocation that holds the path. The presumed and correct behavior would be to plainly ignore the second set of the cookie since it was already set as secure on a secure host so overriding it on an insecure host should not be okay.

By default, curl automatically responds to WebSocket PING frames. Because curl lacks an upper bound on memory allocation for unacknowledged frames, a malicious server can exhaust all available memory by flooding curl with rapid, sequential PING messages.

Using libcurl, when a custom `Host:` header is first set for an HTTP request and a second request is subsequently done using the same *easy handle* but without the custom `Host:` header set, the second request would use stale information and pass on cookies meant for the first host in the second request. Leak them.

When doing a second SMB request to the same host again, curl would wrongly use a data pointer pointing into already freed memory.

When curl retrieves an HTTP response, it stores the incoming headers so that they can be accessed later via the libcurl headers API. However, curl did not have a limit in how many or how large headers it would accept in a response, allowing a malicious server to stream an endless series of headers and eventually cause curl to run out of heap memory.

libcurl's ASN1 parser has this utf8asn1str() function used for parsing an ASN.1 UTF-8 string. Itcan detect an invalid field and return error. Unfortunately, when doing so it also invokes `free()` on a 4 byte localstack buffer. Most modern malloc implementations detect this error and immediately abort. Some however accept the input pointer and add that memory to its list of available chunks. This leads to the overwriting of nearby stack memory. The content of the overwrite is decided by the `free()` implementation; likely to be memory pointers and a set of flags. The most likely outcome of exploting this flaw is a crash, although it cannot be ruled out that more serious results can be had in special circumstances.

libcurl-using applications can ask for a specific client certificate to be used in a transfer. This is done with the `CURLOPT_SSLCERT` option (`--cert` with the command line tool).When libcurl is built to use the macOS native TLS library Secure Transport, an application can ask for the client certificate by name or with a file name - using the same option. If the name exists as a file, it will be used instead of by name.If the appliction runs with a current working directory that is writable by other users (like `/tmp`), a malicious user can create a file name with the same name as the app wants to use by name, and thereby trick the application to use the file based cert instead of the one referred to by name making libcurl send the wrong client certificate in the TLS connection handshake.

curl 7.21.0 to and including 7.73.0 is vulnerable to uncontrolled recursion due to a stack overflow issue in FTP wildcard match parsing.

Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in Apache NimBLE.  Specially crafted GATT operation can cause infinite loop in GATT server leading to denial of service in Bluetooth stack or device. This issue affects Apache NimBLE: through 1.6.0. Users are recommended to upgrade to version 1.7.0, which fixes the issue.

Infinite loop while decoding compressed data can lead to overrun condition in Snapdragon Auto, Snapdragon Compute, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon IoT, Snapdragon Mobile, Snapdragon Voice & Music, Snapdragon Wearables in APQ8009, APQ8017, APQ8053, APQ8096AU, APQ8098, MDM9150, MDM9205, MDM9206, MDM9607, MDM9615, MDM9625, MDM9635M, MDM9640, MDM9650, MDM9655, MSM8905, MSM8909, MSM8909W, MSM8917, MSM8920, MSM8937, MSM8939, MSM8940, MSM8953, MSM8976, MSM8996AU, MSM8998, Nicobar, QCM2150, QCS605, QM215, SC8180X, SDA660, SDA845, SDM429, SDM439, SDM450, SDM630, SDM632, SDM636, SDM660, SDM670, SDM710, SDM845, SDM850, SDX20, SDX24, SDX55, SM6150, SM7150, SM8150, SM8250, Snapdragon_High_Med_2016, SXR1130, SXR2130

Transient DOS when NAS receives ODAC criteria of length 1 and type 1 in registration accept OTA.

tcpreplay v4.4.4 was discovered to contain an infinite loop via the tcprewrite function at get.c.

handler/ssl/OpenSslEngine.java in Netty 4.0.x before 4.0.37.Final and 4.1.x before 4.1.1.Final allows remote attackers to cause a denial of service (infinite loop).

scapy 2.4.0 is affected by: Denial of Service. The impact is: infinite loop, resource consumption and program unresponsive. The component is: _RADIUSAttrPacketListField.getfield(self..). The attack vector is: over the network or in a pcap. both work.

In Apache Thrift all versions up to and including 0.12.0, a server or client may run into an endless loop when feed with specific input data. Because the issue had already been partially fixed in version 0.11.0, depending on the installed version it affects only certain language bindings.

NLnet Labs Unbound version 1.18.0 up to and including version 1.19.1 contain a vulnerability that can cause denial of service by a certain code path that can lead to an infinite loop. Unbound 1.18.0 introduced a feature that removes EDE records from responses with size higher than the client's advertised buffer size. Before removing all the EDE records however, it would try to see if trimming the extra text fields on those records would result in an acceptable size while still retaining the EDE codes. Due to an unchecked condition, the code that trims the text of the EDE records could loop indefinitely. This happens when Unbound would reply with attached EDE information on a positive reply and the client's buffer size is smaller than the needed space to include EDE records. The vulnerability can only be triggered when the 'ede: yes' option is used; non default configuration. From version 1.19.2 on, the code is fixed to avoid looping indefinitely.

In Wireshark 2.2.0 to 2.2.12 and 2.4.0 to 2.4.4, the DMP dissector could go into an infinite loop. This was addressed in epan/dissectors/packet-dmp.c by correctly supporting a bounded number of Security Categories for a DMP Security Classification.

A vulnerability in Drupal Core allows Excessive Allocation.This issue affects Drupal Core: from 10.2.0 before 10.2.2, from 10.1.0 before 10.1.8.

The sequoia-openpgp crate 1.13.0 before 1.21.0 for Rust allows an infinite loop of "Reading a cert: Invalid operation: Not a Key packet" messages for RawCertParser operations that encounter an unsupported primary key type.

In the Linux kernel, the following vulnerability has been resolved: wifi: wlcore: Return -ENOMEM instead of -EAGAIN if there is not enough headroom Since upstream commit e75665dd0968 ("wifi: wlcore: ensure skb headroom before skb_push"), wl1271_tx_allocate() and with it wl1271_prepare_tx_frame() returns -EAGAIN if pskb_expand_head() fails. However, in wlcore_tx_work_locked(), a return value of -EAGAIN from wl1271_prepare_tx_frame() is interpreted as the aggregation buffer being full. This causes the code to flush the buffer, put the skb back at the head of the queue, and immediately retry the same skb in a tight while loop. Because wlcore_tx_work_locked() holds wl->mutex, and the retry happens immediately with GFP_ATOMIC, this will result in an infinite loop and a CPU soft lockup. Return -ENOMEM instead so the packet is dropped and the loop terminates. The problem was found by an experimental code review agent based on gemini-3.1-pro while reviewing backports into v6.18.y.

parser.c in libxml2 before 2.9.5 does not prevent infinite recursion in parameter entities.

An issue was discovered in picoTCP and picoTCP-NG through 1.7.0. When an unsupported TCP option with zero length is provided in an incoming TCP packet, it is possible to cause a Denial-of-Service by achieving an infinite loop in the code that parses TCP options, aka tcp_parse_options() in pico_tcp.c.

A flaw was found in undertow. This issue makes achieving a denial of service possible due to an unexpected handshake status updated in SslConduit, where the loop never terminates.

Improper file stream access in /desktop_app/file.ajax.php?action=uploadfile in Bitrix24 22.0.300 allows unauthenticated remote attackers to cause denial-of-service via a crafted "tmp_url".

When calling bson_utf8_validate on some inputs a loop with an exit condition that cannot be reached may occur, i.e. an infinite loop. This issue affects All MongoDB C Driver versions prior to versions 1.25.0.

QEMU can have an infinite loop in hw/rdma/vmw/pvrdma_dev_ring.c because return values are not checked (and -1 is mishandled).

Infinite loop in Read in crypto/rand before Go 1.17.11 and Go 1.18.3 on Windows allows attacker to cause an indefinite hang by passing a buffer larger than 1 << 32 - 1 bytes.

A flaw was found in libXpm. This issue occurs when parsing a file with a comment not closed; the end-of-file condition will not be detected, leading to an infinite loop and resulting in a Denial of Service in the application linked to the library.

The dwarf_get_aranges_list function in libdwarf before 20160923 allows remote attackers to cause a denial of service (infinite loop and crash) via a crafted DWARF section.

A flaw was found in libXpm. When processing a file with width of 0 and a very large height, some parser functions will be called repeatedly and can lead to an infinite loop, resulting in a Denial of Service in the application linked to the library.

The html package (aka x/net/html) through 2018-09-25 in Go mishandles <table><math><select><mi><select></table>, leading to an infinite loop during an html.Parse call because inSelectIM and inSelectInTableIM do not comply with a specification.

image-size through 2.0.2 contains a denial of service vulnerability that allows remote attackers to permanently block the Node.js event loop by supplying a specially crafted image buffer with a zero-valued size field in a recognized box-type. Attackers can trigger an infinite loop in the JXL or HEIF image parsers by providing a crafted image containing a box with a size of zero, causing the offset to never advance and permanently hanging the application.

pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.3, the `pyasn1` library is vulnerable to a Denial of Service (DoS) attack caused by uncontrolled recursion when decoding ASN.1 data with deeply nested structures. An attacker can supply a crafted payload containing thousands of nested `SEQUENCE` (`0x30`) or `SET` (`0x31`) tags with "Indefinite Length" (`0x80`) markers. This forces the decoder to recursively call itself until the Python interpreter crashes with a `RecursionError` or consumes all available memory (OOM), crashing the host application. This is a distinct vulnerability from CVE-2026-23490 (which addressed integer overflows in OID decoding). The fix for CVE-2026-23490 (`MAX_OID_ARC_CONTINUATION_OCTETS`) does not mitigate this recursion issue. Version 0.6.3 fixes this specific issue.

When processing HTTP/2 SETTINGS frames, transport will enter an infinite loop of writing CONTINUATION frames if it receives a SETTINGS_MAX_FRAME_SIZE with a value of 0.

iskorotkov/avro is a fast Go Avro codec. Prior to 2.33.0, the Avro array and map decoders looped over an attacker-controlled block-count value without checking the underlying reader's error state inside the loop body. Reader.ReadBlockHeader returns the count as a Go int, which is 64-bit on amd64 / arm64 targets — so a producer can declare a block of up to math.MaxInt64 (~9.2 × 10¹⁸) elements followed by EOF (or any truncated payload), and the decoder will attempt that many no-op iterations before propagating the error. The realistic ceiling is "indefinite until the worker is killed externally" — a single hostile payload pins a CPU core until the process is OOM-killed, deadline-cancelled, or terminated. Remote, unauthenticated denial-of-service. This vulnerability is fixed in 2.33.0.

Versions of the package jsrsasign before 11.1.1 are vulnerable to Infinite loop via the bnModInverse function in ext/jsbn2.js when the BigInteger.modInverse implementation receives zero or negative inputs, allowing an attacker to hang the process permanently by supplying such crafted values (e.g., modInverse(0, m) or modInverse(-1, m)).

libjpeg commit 281daa9 was discovered to contain an infinite loop via the component Frame::ParseTrailer.

This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of Unified Automation OPC UA C++ Demo Server 1.7.6-537 [with vendor rollup]. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of certificates. A crafted certificate can force the server into an infinite loop. An attacker can leverage this vulnerability to create a denial-of-service condition on the system. Was ZDI-CAN-17203.

Aardvark-dns is an authoritative dns server for A/AAAA container records. From 1.16.0 to 1.17.0, a truncated TCP DNS query followed by a connection reset causes aardvark-dns to enter an unrecoverable infinite error loop at 100% CPU. This vulnerability is fixed in 1.17.1.

Forge (also called `node-forge`) is a native implementation of Transport Layer Security in JavaScript. Prior to version 1.4.0, a Denial of Service (DoS) vulnerability exists in the node-forge library due to an infinite loop in the BigInteger.modInverse() function (inherited from the bundled jsbn library). When modInverse() is called with a zero value as input, the internal Extended Euclidean Algorithm enters an unreachable exit condition, causing the process to hang indefinitely and consume 100% CPU. Version 1.4.0 patches the issue.

pypdf is a free and open-source pure-python PDF library. Versions prior to 6.9.2 have a vulnerability in which an attacker can craft a PDF which leads to an infinite loop. This requires reading a file in non-strict mode. This has been fixed in pypdf 6.9.2. If users cannot upgrade yet, consider applying the changes from the patch manually.

Vulnerability in the Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition product of Oracle Java SE (component: Networking). Supported versions that are affected are Oracle Java SE: 8u481-perf, 11.0.30, 17.0.18, 21.0.10, 25.0.2, 26; Oracle GraalVM for JDK: 17.0.18 and 21.0.10; Oracle GraalVM Enterprise Edition: 21.3.17. Easily exploitable vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition. Note: This vulnerability can be exploited by using APIs in the specified Component, e.g., through a web service which supplies data to the APIs. This vulnerability also applies to Java deployments, typically in clients running sandboxed Java Web Start applications or sandboxed Java applets, that load and run untrusted code (e.g., code that comes from the internet) and rely on the Java sandbox for security. CVSS 3.1 Base Score 7.5 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Versions 5.10 through 5.11.0 are vulnerable to buffer overflow or infinite loop through large indent handling. ujson.dumps() crashes the Python interpreter (segmentation fault) when the product of the indent parameter and the nested depth of the input exceeds INT32_MAX. It can also get stuck in an infinite loop if the indent is a large negative number. Both are caused by an integer overflow/underflow whilst calculating how much memory to reserve for indentation. And both can be used to achieve denial of service. To be vulnerable, a service must call ujson.dump()/ujson.dumps()/ujson.encode() whilst giving untrusted users control over the indent parameter and not restrict that indentation to reasonably small non-negative values. A service may also be vulnerable to the infinite loop if it uses a fixed negative indent. An underflow always occurs for any negative indent when the input data is at least one level nested but, for small negative indents, the underflow is usually accidentally rectified by another overflow. This issue has been fixed in version 5.12.0.