WEBrick::HTTPAuth::DigestAuth in Ruby through 2.4.7, 2.5.x through 2.5.6, and 2.6.x through 2.6.4 has a regular expression Denial of Service cause by looping/backtracking. A victim must expose a WEBrick server that uses DigestAuth to the Internet or a untrusted network.

REXML is an XML toolkit for Ruby. The REXML gem before 3.3.9 has a ReDoS vulnerability when it parses an XML that has many digits between &# and x...; in a hex numeric character reference (&#x...;). This does not happen with Ruby 3.2 or later. Ruby 3.1 is the only affected maintained Ruby. The REXML gem 3.3.9 or later include the patch to fix the vulnerability.

REXML is an XML toolkit for Ruby. The REXML gem 3.3.2 has a DoS vulnerability when it parses an XML that has many entity expansions with SAX2 or pull parser API. The REXML gem 3.3.3 or later include the patch to fix the vulnerability.

Rails is a web-application framework. Starting in version 7.1.0, there is a possible ReDoS vulnerability in the Accept header parsing routines of Action Dispatch. This vulnerability is patched in 7.1.3.1. Ruby 3.2 has mitigations for this problem, so Rails applications using Ruby 3.2 or newer are unaffected.

Date.parse in the date gem through 3.2.0 for Ruby allows ReDoS (regular expression Denial of Service) via a long string. The fixed versions are 3.2.1, 3.1.2, 3.0.2, and 2.0.1.

A regular expression based DoS vulnerability in Action Dispatch <6.1.7.1 and <7.0.4.1 related to the If-None-Match header. A specially crafted HTTP If-None-Match header can cause the regular expression engine to enter a state of catastrophic backtracking, when on a version of Ruby below 3.2.0. This can cause the process to use large amounts of CPU and memory, leading to a possible DoS vulnerability All users running an affected release should either upgrade or use one of the workarounds immediately.

JSON is a JSON implementation for Ruby. Starting in version 2.10.0 and prior to version 2.10.2, a specially crafted document could cause an out of bound read, most likely resulting in a crash. Versions prior to 2.10.0 are not vulnerable. Version 2.10.2 fixes the problem. No known workarounds are available.

In the CGI gem before 0.4.2 for Ruby, a Regular Expression Denial of Service (ReDoS) vulnerability exists in the Util#escapeElement method.

In the CGI gem before 0.4.2 for Ruby, the CGI::Cookie.parse method in the CGI library contains a potential Denial of Service (DoS) vulnerability. The method does not impose any limit on the length of the raw cookie value it processes. This oversight can lead to excessive resource consumption when parsing extremely large cookies.

An issue was discovered in Oniguruma 6.2.0, as used in Oniguruma-mod in Ruby through 2.4.1 and mbstring in PHP through 7.1.5. A SIGSEGV occurs in left_adjust_char_head() during regular expression compilation. Invalid handling of reg->dmax in forward_search_range() could result in an invalid pointer dereference, normally as an immediate denial-of-service condition.

REXML is an XML toolkit for Ruby. The REXML gem before 3.3.2 has some DoS vulnerabilities when it parses an XML that has many specific characters such as whitespace character, `>]` and `]>`. The REXML gem 3.3.3 or later include the patches to fix these vulnerabilities.

Nordic Semiconductor IronSide SE for nRF54H20 before 23.0.2+17 has an Algorithmic complexity issue.

Pathway through 0.31.1, fixed in commit d09722e, document store applies a caller-supplied glob pattern to indexed document paths using a hand-written recursive matcher that branches two ways on each ** token without memoization, giving exponential worst-case complexity. The filepath_globpattern value is taken from the body of the unauthenticated HTTP endpoints /v1/retrieve, /v1/inputs and /v2/answer and compiled into a filter evaluated once per indexed document, with no length or **-count limit. A remote unauthenticated attacker can submit a short pattern containing many ** tokens to consume CPU for tens of seconds per request, and a small number of requests denies service.

An issue was discovered in 6.0 before 6.0.2, 5.2 before 5.2.11, and 4.2 before 4.2.28. `ASGIRequest` allows a remote attacker to cause a potential denial-of-service via a crafted request with multiple duplicate headers. Earlier, unsupported Django series (such as 5.0.x, 4.1.x, and 3.2.x) were not evaluated and may also be affected. Django would like to thank Jiyong Yang for reporting this issue.

cmark-gfm is GitHub's fork of cmark, a CommonMark parsing and rendering library and program in C. In versions prior to 0.29.0.gfm.6 a polynomial time complexity issue in cmark-gfm's autolink extension may lead to unbounded resource exhaustion and subsequent denial of service. Users may verify the patch by running `python3 -c 'print("![l"* 100000 + "\n")' | ./cmark-gfm -e autolink`, which will resource exhaust on unpatched cmark-gfm but render correctly on patched cmark-gfm. This vulnerability has been patched in 0.29.0.gfm.6. Users are advised to upgrade. Users unable to upgrade should disable the use of the autolink extension.

Inefficient algorithm complexity in mjson in HAProxy allows remote attackers to cause a denial of service via specially crafted JSON requests.

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Utils.select_best_encoding processes Accept-Encoding values with quadratic time complexity when the header contains many wildcard (*) entries. Because this method is used by Rack::Deflater to choose a response encoding, an unauthenticated attacker can send a single request with a crafted Accept-Encoding header and cause disproportionate CPU consumption on the compression middleware path. This results in a denial of service condition for applications using Rack::Deflater. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.

An issue was discovered in GitLab CE/EE affecting all versions starting from 13.6 prior to 17.2.9, starting from 17.3 prior to 17.3.5, and starting from 17.4 prior to 17.4.2, where viewing diffs of MR with conflicts can be slow.

An issue has been discovered in GitLab CE/EE affecting all versions from 9.4 before 17.4.6, 17.5 before 17.5.4, and 17.6 before 17.6.2. An attacker could cause a denial of service with requests for diff files on a commit or merge request.

An issue was discovered in GitLab CE/EE affecting all versions starting from 15.6 prior to 17.4.5, starting from 17.5 prior to 17.5.3, starting from 17.6 prior to 17.6.1 which could cause Denial of Service via integrating a malicious harbor registry.

A Denial of Service (DoS) issue has been discovered in GitLab CE/EE affecting all versions prior to 12.6 prior to 17.4.5, 17.5 prior to 17.5.3, and 17.6 prior to 17.6.1. An attacker could cause a denial of service with a crafted cargo.toml file.

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.30, when parsing application/x-www-form-urlencoded bodies, QuerystringParser located the field separator with a two step lookup: it first scanned the entire remaining buffer for &, and only when no & existed anywhere ahead did it fall back to scanning for ;. For a body that uses ; as the separator and contains no &, every field iteration performed a full failed & scan over the entire remaining buffer before locating the nearby ;. With N semicolon separated fields in a chunk of size B, this yields O(B^2) byte comparisons per chunk. An attacker can submit a small crafted body of the form a;a;a;... and cause the parser to spend seconds of CPU per request. A handful of concurrent requests can exhaust worker processes. This vulnerability is fixed in 0.0.30.

.NET, .NET Framework, and Visual Studio Denial of Service Vulnerability

.NET and Visual Studio Denial of Service Vulnerability

.NET, .NET Framework, and Visual Studio Denial of Service Vulnerability

An issue was discovered in 5.2 before 5.2.9, 5.1 before 5.1.15, and 4.2 before 4.2.27. Algorithmic complexity in `django.core.serializers.xml_serializer.getInnerText()` allows a remote attacker to cause a potential denial-of-service attack triggering CPU and memory exhaustion via specially crafted XML input processed by the XML `Deserializer`. Earlier, unsupported Django series (such as 5.0.x, 4.1.x, and 3.2.x) were not evaluated and may also be affected. Django would like to thank Seokchan Yoon for reporting this issue.

Inefficient algorithmic complexity in DecodeFromBytes function in com.upokecenter.cbor Java implementation of Concise Binary Object Representation (CBOR) versions 4.0.0 to 4.5.1 allows an attacker to cause a denial of service by passing a maliciously crafted input. Depending on an application's use of this library, this may be a remote attacker.

An Insufficient Algorithmic Complexity combined with an Allocation of Resources Without Limits or Throttling vulnerability in the flow processing daemon (flowd) of Juniper Networks Junos OS on SRX Series and MX Series with SPC3 allows an unauthenticated network attacker to cause latency in transit packet processing and even packet loss. If transit traffic includes a significant percentage (> 5%) of fragmented packets which need to be reassembled, high latency or packet drops might be observed. This issue affects Juniper Networks Junos OS on SRX Series, MX Series with SPC3: All versions prior to 18.2R3; 18.3 versions prior to 18.3R3; 18.4 versions prior to 18.4R2-S9, 18.4R3; 19.1 versions prior to 19.1R2; 19.2 versions prior to 19.2R1-S1, 19.2R2.

fzf is vulnerable to a Denial of Service (DoS) due to inefficient HTTP body processing in the --listen mode due to inefficient HTTP body processing using repeated string concatenation, resulting in quadratic time complexity (O(n²)). A crafted POST request with many small segments can trigger excessive CPU usage during request handling.This allows a single malicious request to monopolize the single‑threaded HTTP server, blocking all other clients and resulting in denial of service. This issue was fixed in version 0.73.1.

PeterO.Cbor versions 4.0.0 through 4.5.0 are vulnerable to a denial of service vulnerability. An attacker may trigger the denial of service condition by providing crafted data to the DecodeFromBytes or other decoding mechanisms in PeterO.Cbor. Depending on the usage of the library, an unauthenticated and remote attacker may be able to cause the denial of service condition.

A denial of service (DoS) condition was discovered in GitLab CE/EE affecting all versions from 13.2.4 before 17.4.5, 17.5 before 17.5.3, and 17.6 before 17.6.1. By leveraging this vulnerability an attacker could create a DoS condition by sending crafted API calls. This was a regression of an earlier patch.

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, Mistune is vulnerable to a CPU exhaustion DoS due to superlinear (approximately O(n²)) behavior in parse_link_text. When parsing Markdown containing many consecutive [ characters, parse_link_text repeatedly scans the input using a regex search inside a loop. Each iteration re-scans a large portion of the remaining string, resulting in quadratic-time behavior. An attacker-controlled Markdown input can therefore trigger excessive CPU usage with a very small payload. This vulnerability is fixed in 3.3.0.

IO::Uncompress::Unzip versions before 2.220 for Perl allow CPU exhaustion via per-byte read loop in fastForward. fastForward() compares length $offset (the digit count of the offset, 1 to 19) against the chunk size $c instead of $offset itself, so $c shrinks from 16 KiB to 1-19 bytes per iteration. Extracting a named entry from an attacker supplied zip via IO::Uncompress::Unzip->new($zip, Name => $target) drives a per-byte read loop scaling with the entry's compressed size, up to the non-Zip64 4 GiB cap.

js-toml is a TOML parser for JavaScript, fully compliant with the TOML 1.0.0 Spec. Versions up to and including 1.1.0 parse hexadecimal / octal / binary integer literals via a hand-written `parseBigInt` loop that multiplies a `BigInt` accumulator by the radix once per input digit. Each iteration performs a `BigInt * BigInt` operation on an accumulator that grows linearly with the number of digits already consumed, so the whole loop is O(n²) in the literal length. The lexer regex places no upper bound on the literal length, so a single TOML document containing one ~500 kB hex literal pins one CPU core for ~40 seconds on a modern laptop (Apple M-series, Node v22). Memory amplification is bounded but CPU amplification is severe and grows quadratically: doubling the literal length quadruples the work. A caller that invokes `load()` on attacker-controlled TOML (configuration upload endpoints, CI/CD systems ingesting third-party `*.toml`, IDE plugins, build tools) is exposed to a single-request CPU exhaustion DoS. Version 1.1.1 fixes the issue.

MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, ExpandoObjectFormatter.Deserialize populates System.Dynamic.ExpandoObject by calling IDictionary<string, object>.Add for each map entry. ExpandoObject internally maintains member names in array-like structures, so inserting many distinct keys can require repeated linear scans and array copies. For large attacker-controlled maps, this produces quadratic CPU and allocation behavior. The issue is especially surprising because ExpandoObjectResolver.Options is configured with MessagePackSecurity.UntrustedData, but collision-resistant dictionary comparers cannot protect ExpandoObject insertion internals. This vulnerability is fixed in 2.5.301 and 3.1.7.

MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, InterfaceLookupFormatter<TKey,TElement> constructs an internal Dictionary<TKey, IGrouping<TKey,TElement>> with the default equality comparer instead of the security-aware comparer supplied by options.Security.GetEqualityComparer<TKey>(). This formatter omission allows hash-collision CPU denial of service against ILookup<TKey,TElement> even when the application has opted into the untrusted-data security posture This vulnerability is fixed in 2.5.301 and 3.1.7.

Werkzeug is a comprehensive WSGI web application library. In versions on the 3.x branch prior to 3.0.1 and on the 2.x branch prior to 2.3.8, if an upload of a file that starts with CR or LF and then is followed by megabytes of data without these characters: all of these bytes are appended chunk by chunk into internal bytearray and lookup for boundary is performed on growing buffer. This allows an attacker to cause a denial of service by sending crafted multipart data to an endpoint that will parse it. The amount of CPU time required can block worker processes from handling legitimate requests. This vulnerability has been patched in version 3.0.1 and 2.3.8.

The DNS message parsing code in `named` includes a section whose computational complexity is overly high. It does not cause problems for typical DNS traffic, but crafted queries and responses may cause excessive CPU load on the affected `named` instance by exploiting this flaw. This issue affects both authoritative servers and recursive resolvers. This issue affects BIND 9 versions 9.0.0 through 9.16.45, 9.18.0 through 9.18.21, 9.19.0 through 9.19.19, 9.9.3-S1 through 9.11.37-S1, 9.16.8-S1 through 9.16.45-S1, and 9.18.11-S1 through 9.18.21-S1.

In libexpat before 2.8.1, the computational complexity of attribute name collision checks allows a denial of service via moderately sized crafted XML input.

ImageMagick is free and open-source software used for editing and manipulating digital images. Prior to versions 6.9.13-47 and 7.1.2-22, because of a missing check in the MNG coder it would be possible to read more images than the list limit policy would allow resulting in excessive resource use. This issue has been patched in versions 6.9.13-47 and 7.1.2-22.

NLnet Labs Unbound up to and including version 1.25.0 has a vulnerability when handling replies with very large RRsets that Unbound needs to perform name compression for. Malicious upstream responses with very large RRsets with records that don't share a suffix above the root can cause Unbound to spend a considerable time applying name compression to downstream replies. This can lead to degraded performance and eventually denial of service in well orchestrated attacks. An adversary can exploit the vulnerability by querying Unbound for the specially crafted contents of a malicious zone with very large RRsets. Before Unbound replies to the query it will try to apply name compression which was an unbounded operation that could lock the CPU until the whole packet was complete. A compression limit was introduced in 1.21.1 for this but it didn't account for the case where records would not share any suffix above the root. That causes Unbound to go in a different code path because of the compression tree lookup failure and eventually not increment the compression counter for those operations. Unbound 1.25.1 contains a patch with a fix that increments the compression counter regardless of the compression tree lookup. This is a complement fix to CVE-2024-8508.

Botan is a C++ cryptography library. Prior to 3.12.0, certain patterns of indefinite length encodings in BER data could cause quadratic behavior in the parser, resulting in a denial of service. Such BER encodings were accepted even in structures which are required to be encoded as DER, which prohibits indefinite length encodings. This vulnerability is fixed in 3.12.0.

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.5 before 18.8.7, 18.9 before 18.9.3, and 18.10 before 18.10.1 that could have allowed an unauthenticated user to cause a denial of service by making the GitLab instance unresponsive due to improper input validation in GraphQL request processing.

Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.4.0rc2, the twisted.names module is vulnerable to a Denial of Service (DoS) attack via resource exhaustion during DNS name decompression. A remote, unauthenticated attacker can exploit this by sending a crafted TCP DNS packet containing deeply chained compression pointers. This flaw bypasses previous loop-prevention logic, causing the single-threaded Twisted reactor to hang while processing millions of recursive lookups, effectively freezing the server. This vulnerability is fixed in 26.4.0rc2.

Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive CPU.

NLnet Labs Unbound up to and including version 1.25.0 is vulnerable to a degradation of service attack related to parsing long lists of incoming EDNS options. An adversary sending queries with too many EDNS options can hold Unbound threads hostage while they are parsing and creating internal data structures for the options. Coordinated attacks can result in degradation and/or denial of service. Unbound 1.25.1 contains a patch with a fix to limit acceptable incoming EDNS options (100).

Applications that evaluate user-supplied Spring Expression Language (SpEL) expressions are vulnerable to an Algorithmic Denial of Service (DoS). By providing a specially crafted expression, an attacker can trigger excessive resource consumption during evaluation, leading to application degradation or unavailability. Affected versions: Spring Framework 7.0.0 through 7.0.7; 6.2.0 through 6.2.18; 6.1.0 through 6.1.27; 5.3.0 through 5.3.48.

jq is a command-line JSON processor. Before commit 0c7d133c3c7e37c00b6d46b658a02244fdd3c784, jq used MurmurHash3 with a hardcoded, publicly visible seed (0x432A9843) for all JSON object hash table operations, which allowed an attacker to precompute key collisions offline. By supplying a crafted JSON object (~100 KB) where all keys hashed to the same bucket, hash table lookups degraded from O(1) to O(n), turning any jq expression into an O(n²) operation and causing significant CPU exhaustion. This affected common jq use cases such as CI/CD pipelines, web services, and data processing scripts, and was far more practical to exploit than existing heap overflow issues since it required only a small payload. This issue has been patched in commit 0c7d133c3c7e37c00b6d46b658a02244fdd3c784.

graphql-go is a Go implementation of GraphQL. In versions 15.31.4 and below, the OverlappingFieldsCanBeMerged validation rule performs O(n²) pairwise comparisons of fields sharing the same response name. An attacker can send a query with thousands of repeated identical fields, causing excessive CPU usage during validation before execution begins. This is not mitigated by existing QueryDepth or QueryComplexity rules. This issue has been fixed in version 15.31.5.