Weakness (CWE)
CWE-1333: Inefficient Regular Expression Complexity
The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.
How to prevent it (4 mitigations)
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Architecture and Design
Use regular expressions that do not support backtracking, e.g. by removing nested quantifiers.
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System Configuration
Set backtracking limits in the configuration of the regular expression implementation, such as PHP's pcre.backtrack_limit. Also consider limits on execution time for the process.
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Implementation
Do not use regular expressions with untrusted input. If regular expressions must be used, avoid using backtracking in the expression.
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Implementation
Limit the length of the input that the regular expression will process.
Source: MITRE CWE-1333
591 results · Feed
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Medium 6.9
Rails Active Support has a possible ReDoS vulnerability in number_to_delimited
Active Support is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework. `NumberToDelimitedConverter` uses a lookahead-based regular expression with `gsub!` to insert thousands delimiters. Prior to versions 8.1.2.1, 8.0.4.…
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Low 3.3
pygments archetype.py AdlLexer redos
A security flaw has been discovered in pygments up to 2.19.2. The impacted element is the function AdlLexer of the file pygments/lexers/archetype.py. The manipulation results in inefficient regular expression complexity. The attack is only possible with local…
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Medium 6.5
OpenClaw < 2026.2.19 - ReDoS and Regex Injection via Unescaped Feishu Mention Metadata
OpenClaw versions prior to 2026.2.19 construct RegExp objects directly from unescaped Feishu mention metadata in the stripBotMention function, allowing regex injection and denial of service. Attackers can craft nested-quantifier patterns or metacharacters in …
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High 7.5
ReDoS in multipart 1.3.0 - `parse_options_header()`
multipart is a fast multipart/form-data parser for python. Prior to 1.2.2, 1.3.1 and 1.4.0-dev, the parse_options_header() function in multipart.py uses a regular expression with an ambiguous alternation, which can cause exponential backtracking (ReDoS) when …
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High 7.5
Elysia has a string URL format redos
Elysia is a Typescript framework for request validation, type inference, OpenAPI documentation and client-server communication. Prior to 1.4.26 , t.String({ format: 'url' }) is vulnerable to ReDoS. Repeating a partial url format (protocol and hostname) multip…
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High 8.2
Parse Server affected by Regular Expression Denial of Service (ReDoS) via `$regex` query in LiveQuery
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.5.0-alpha.14 and 8.6.11, a malicious client can subscribe to a LiveQuery with a crafted $regex pattern that causes catastrophic backtracking, bl…
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High 7.5
An issue pertaining to CWE-1333: Inefficient Regular Expression Complexity (4.19) was discovered in Sunbird-Ed SunbirdE…
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High 7.5
An issue pertaining to CWE-1333: Inefficient Regular Expression Complexity (4.19) was discovered in mscdex ssh2 v1.17.0.
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Medium 5.9
cpp-httplib: Stack Overflow Denial of Service (DoS) via std::regex in multipart filename parsing
cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to version 0.37.0, cpp-httplib uses std::regex (libstdc++) to parse RFC 5987 encoded filename* values in multipart Content-Disposition headers. The regex engine in libstdc…
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High 7.5
Rexml: rexml: denial of service via inefficient regex parsing
A flaw was found in REXML. A remote attacker could exploit inefficient regular expression (regex) parsing when processing hex numeric character references (&#x...;) in XML documents. This could lead to a Regular Expression Denial of Service (ReDoS), impacting…
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Low 3.3
snowflakedb snowflake-jdbc JDBC URL SdkProxyRoutePlanner.java SdkProxyRoutePlanner redos
A weakness has been identified in snowflakedb snowflake-jdbc up to 4.0.1. Impacted is the function SdkProxyRoutePlanner of the file src/main/java/net/snowflake/client/internal/core/SdkProxyRoutePlanner.java of the component JDBC URL Handler. Executing a manip…
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Medium 4.9
Inefficient Regular Expression Complexity in Kibana Leading to Denial of Service
Inefficient Regular Expression Complexity (CWE-1333) in the AI Inference Anonymization Engine in Kibana can lead Denial of Service via Regular Expression Exponential Blowup (CAPEC-492).
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High 7.5
minimatch ReDoS: nested *() extglobs generate catastrophically backtracking regular expressions
minimatch is a minimal matching utility for converting glob expressions into JavaScript RegExp objects. Prior to version 10.2.3, 9.0.7, 8.0.6, 7.4.8, 6.2.2, 5.1.8, 4.2.5, and 3.1.4, nested `*()` extglobs produce regexps with nested unbounded quantifiers (e.g.…
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High 7.5
Inefficient Regular Expression Complexity in GitLab
GitLab has remediated an issue in GitLab CE/EE affecting all versions from 9.2 before 18.7.5, 18.8 before 18.8.5, and 18.9 before 18.9.1 that could have allowed an unauthenticated user to cause regular expression denial of service by sending specially crafted…
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High 8.7
minimatch has a ReDoS via repeated wildcards with non-matching literal in pattern
minimatch is a minimal matching utility for converting glob expressions into JavaScript RegExp objects. Versions 10.2.0 and below are vulnerable to Regular Expression Denial of Service (ReDoS) when a glob pattern contains many consecutive * wildcards followed…
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Medium 5.3
markdown-it is has a Regular Expression Denial of Service (ReDoS)
Versions of the package markdown-it from 13.0.0 and before 14.1.1 are vulnerable to Regular Expression Denial of Service (ReDoS) due to the use of the regex /\*+$/ in the linkify function. An attacker can supply a long sequence of * characters followed by a n…
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Low 2.9
ajv has ReDoS when using `$data` option
ajv (Another JSON Schema Validator) before 8.18.0 is vulnerable to Regular Expression Denial of Service (ReDoS) when the $data option is enabled. The pattern keyword accepts runtime data via JSON Pointer syntax ($data reference), which is passed directly to t…
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Medium 6.5
Redos (Regular Expression Denial of Service) at Code Extraction Block in significant-gravitas/autogpt
AutoGPT is a platform that allows users to create, deploy, and manage continuous artificial intelligence agents that automate complex workflows. The autogpt before 0.6.32 is vulnerable to Regular Expression Denial of Service due to the use of regex at Code Ex…
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Critical 9.2
Uncontrolled Resource Consumption in @isaacs/brace-expansion
@isaacs/brace-expansion is a hybrid CJS/ESM TypeScript fork of brace-expansion. Prior to version 5.0.1, @isaacs/brace-expansion is vulnerable to a denial of service (DoS) issue caused by unbounded brace range expansion. When an attacker provides a pattern con…
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High 7.5
Apollo Server is vulnerable to denial of service with `startStandaloneServer`
Apollo Server is an open-source, spec-compliant GraphQL server that's compatible with any GraphQL client, including Apollo Client. In versions from 2.0.0 to 3.13.0, 4.2.0 to before 4.13.0, and 5.0.0 to before 5.4.0, the default configuration of startStandalon…
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Low 2.7
jsdiff has a Denial of Service vulnerability in parsePatch and applyPatch
jsdiff is a JavaScript text differencing implementation. Prior to versions 8.0.3, 5.2.2, 4.0.4, and 3.5.1, attempting to parse a patch whose filename headers contain the line break characters `\r`, `\u2028`, or `\u2029` can cause the `parsePatch` method to en…
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High 7.5
seroval affected by Denial of Service via RegExp serialization
seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities. In versions 0.2.0 through 1.4.0, overriding RegExp serialization with extremely large patterns can exhaust JavaScript runtime memory during deserial…
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Medium 4.4
tarteaucitron.js has Regular Expression Denial of Service (ReDoS) vulnerability
tarteaucitron.js is a compliant and accessible cookie banner. Prior to 1.29.0, a Regular Expression Denial of Service (ReDoS) vulnerability was identified in tarteaucitron.js in the handling of the issuu_id parameter. This vulnerability is fixed in 1.29.0.
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High 8.7
LangChain <= 0.3.1 MRKLOutputParser ReDoS
LangChain versions up to and including 0.3.1 contain a regular expression denial-of-service (ReDoS) vulnerability in the MRKLOutputParser.parse() method (libs/langchain/langchain/agents/mrkl/output_parser.py). The parser applies a backtracking-prone regular e…
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Low 2.7
pypdf has possible long runtimes for malformed startxref
pypdf is a free and open-source pure-python PDF library. Prior to version 6.6.0, pypdf has possible long runtimes for malformed startxref. An attacker who uses this vulnerability can craft a PDF which leads to possibly long runtimes for invalid startxref entr…
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High 7.5
Flag Forge has ReDoS Vulnerability in User Profile Lookup API
Flag Forge is a Capture The Flag (CTF) platform. Versions 2.3.2 and below have a Regular Expression Denial of Service (ReDoS) vulnerability in the user profile API endpoint (/api/user/[username]). The application constructs a regular expression dynamically us…
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Medium 5.3
VisualData extension: Regular Expression Denial of Service (ReDoS) via crafted user input
Inefficient Regular Expression Complexity vulnerability in Wikimedia Foundation MediaWiki - VisualData Extension allows Regular Expression Exponential Blowup.This issue affects MediaWiki - VisualData Extension: 1.45.
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High 8.7
MCP TypeScript SDK UriTemplate Exploded Array Pattern ReDoS
Anthropic's MCP TypeScript SDK versions up to and including 1.25.1 contain a regular expression denial of service (ReDoS) vulnerability in the UriTemplate class when processing RFC 6570 exploded array patterns. The dynamically generated regular expression use…
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High 7.5
Fedify has ReDoS Vulnerability in HTML Parsing Regex
Fedify is a TypeScript library for building federated server apps powered by ActivityPub. Prior to versions 1.6.13, 1.7.14, 1.8.15, and 1.9.2, a Regular Expression Denial of Service (ReDoS) vulnerability exists in Fedify's document loader. The HTML parsing re…
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Low 2.7
PyMdown Extensions has ReDOS bug in Figure Capture extension
PyMdown Extensions is a set of extensions for the `Python-Markdown` markdown project. Versions prior to 10.16.1 have a ReDOS bug found within the figure caption extension (`pymdownx.blocks.caption`). In systems that take unchecked user content, this could cau…
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High 7.5
Valibot has a ReDoS vulnerability in `EMOJI_REGEX`
Valibot helps validate data using a schema. In versions from 0.31.0 to 1.1.0, the EMOJI_REGEX used in the emoji action is vulnerable to a Regular Expression Denial of Service (ReDoS) attack. A short, maliciously crafted string (e.g., <100 characters) can caus…
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High 8.1
Zoom Workplace Clients - Inefficient Regular Expression Complexity
Inefficient regular expression complexity in certain Zoom Workplace Clients before version 6.5.10 may allow an unauthenticated user to conduct an escalation of privilege via network access.
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High 7.5
Apache Traffic Control: ReDoS issue in Traffic Router configuration
** UNSUPPORTED WHEN ASSIGNED ** Inefficient Regular Expression Complexity vulnerability in Apache Traffic Control. This issue affects Apache Traffic Control: all versions. People with access to the management interface of the Traffic Router component could sp…
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Low 2.7
Sinatra has ReDoS vulnerability in ETag header value generation
Sinatra is a domain-specific language for creating web applications in Ruby. In versions prior to 4.2.0, there is a denial of service vulnerability in the `If-Match` and `If-None-Match` header parsing component of Sinatra, if the `etag` method is used when co…
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Medium 5.3
Regular Expression Denial of Service (ReDoS) in huggingface/transformers
A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the Hugging Face Transformers library, specifically within the `normalize_numbers()` method of the `EnglishNormalizer` class. This vulnerability affects versions up to 4.52.4 and i…
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Medium 5.3
Regular Expression Denial of Service (ReDoS) in huggingface/transformers
A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the Hugging Face Transformers library, specifically affecting the MarianTokenizer's `remove_language_code()` method. This vulnerability is present in version 4.52.4 and has been fi…
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High 8.7
Cattown Vulnerable to Inefficient Regular Expression Complexity and Uncontrolled Resource Consumption
Cattown is a JavaScript markdown parser. Versions prior to 1.0.2 used regular expressions with inefficient, potentially exponential worst-case complexity. This could cause excessive CPU usage due to excessive backtracking on crafted inputs. In turn, the exces…
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Medium 5.3
mixmark-io turndown commonmark-rules.js redos
A security flaw has been discovered in mixmark-io turndown up to 7.2.1. This affects an unknown function of the file src/commonmark-rules.js. Performing manipulation results in inefficient regular expression complexity. It is possible to initiate the attack r…
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Medium 6.9
Liferay Portal ReDoS with Role Name search in KaleoDesignerPortlet
Self-ReDoS (Regular expression Denial of Service) exists with Role Name search field of Kaleo Designer portlet JavaScript in Liferay Portal 7.4.0 through 7.4.3.131, and Liferay DXP 2024.Q4.0 through 2024.Q4.1, 2024.Q3.0 through 2024.Q3.13, 2024.Q2.1 through 2…
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Low 3.3
yarnpkg Yarn request-manager.js setOptions redos
A vulnerability has been found in yarnpkg Yarn up to 1.22.22. This impacts the function setOptions of the file src/util/request-manager.js. Such manipulation leads to inefficient regular expression complexity. Local access is required to approach this attack.…