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
256 results · Clear filters · Feed
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Medium 5.9
Forge: ReDoS in forge.http response header and cookie trimming
Forge (also called node-forge) is a native implementation of Transport Layer Security in JavaScript. From 0.1.2 until 1.4.3, forge.http uses _trimString() in lib/http.js to remove trailing whitespace from response header values and cookie names and values wit…
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Medium 6.5
Gst-plugins-base: gst-plugins-base: quadratic regex processing in srt/webvtt subtitle parser causes denial of service
A flaw was found in the SRT and WebVTT subtitle parser in GStreamer's gst-plugins-base. While sanitizing inline subtitle markup, the parser repeatedly searches the remaining text with unanchored regular expressions. A crafted subtitle cue with a long line of …
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Medium 4.3
Automation-controller: automation-controller: quadratic regex in schedule rrule validation allows an authenticated user to exhaust api web workers (denial of service)
A flaw was found in the rrule validation of schedules in automation controller. Several non-anchored regular expressions with lazy wildcard prefixes are applied to the user-supplied rrule value; when the expected DTSTART/RRULE tokens are absent, validation ti…
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Medium 6.5
CGI versions before 5.00 for Perl allow CPU exhaustion via a backtracking regex on the XForms multipart/related Content-Type
CGI versions before 5.00 for Perl allow CPU exhaustion via a backtracking regex on the XForms multipart/related Content-Type. When a POST Content-Type contains multipart/related, the boundary and start parameters are extracted with an unanchored pattern that …
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Medium 6.7
Unescaped header separators in whatstk build a regular expression that backtracks exponentially
Inefficient Regular Expression Complexity (CWE-1333) in generate_regex() (whatstk/whatsapp/parser.py) in whatstk from 0.2.0 before 0.9.0 allows a party that supplies a chat export to consume the CPU of the process that parses it for an unbounded time, because…
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Medium 4.3
Delgan loguru ANSI Color-Markup _colorizer.py AnsiParser.feed redos
A vulnerability was detected in Delgan loguru 0.7.3. The affected element is the function AnsiParser.feed of the file loguru/_colorizer.py of the component ANSI Color-Markup Parser. Performing a manipulation results in inefficient regular expression complexit…
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Medium 6.5
Wekan: ReDoS via Unescaped User Input in RegExp
Wekan is open source kanban built with Meteor. Prior to 11.11, the user-search publication in server/publications/users.js and the searchUsers method in server/models/users.js pass authenticated user-controlled searchTerm and query values to new RegExp() with…
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Medium 6.5
n8n before 1.123.85, 2.43.5, and 2.44.1 ReDoS via Read/Write Files Node
n8n before 1.123.85, 2.43.5, and 2.44.1 contains a regular expression denial of service vulnerability that allows authenticated members to block the event loop via crafted glob patterns. Attackers who can create and run workflows can submit a wildcard-heavy F…
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Medium 5.3
opentelemetry-java: Quadratic CPU consumption in W3C tracestate parsing
opentelemetry-java is the Java implementation of the OpenTelemetry API for recording telemetry, and SDK for managing telemetry recorded by the API. Prior to 1.67.0, W3CTraceContextPropagator.extract() uses regex delimiter processing that can exhibit quadratic…
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Medium 6.5
Crawl4AI 0.7.0 before 0.9.5 ReDoS via /crawl Regex Fields
Crawl4AI 0.7.0 before 0.9.5 contains an inefficient regular expression complexity vulnerability in the Docker API server that allows authenticated API clients to supply unbounded regular expressions in /crawl request bodies. Attackers can submit catastrophic-…
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Medium 5.3
OpenTelemetry Python: Unbounded tracestate parsing in opentelemetry-api
OpenTelemetry Python provides the Python API and SDK for OpenTelemetry. Prior to 1.45.1, the opentelemetry-api function TraceState.from_header in opentelemetry/trace/span.py, reached through TraceContextTextMapPropagator.extract, parses inbound W3C tracestate…
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Medium 6.9
Pillow: ReDoS in XbmImagePlugin: 512-byte file stalls Image.open() for minutes
Pillow is a Python imaging library. Prior to 13.0.0, Pillow's XBM header parser is vulnerable to regular-expression denial of service. In XbmImageFile._open, when an application calls Image.open() on a small crafted XBM file, XbmImagePlugin applies a backtrac…
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Medium 5.3
DiffSK configobj __init__.py _sectionmarker redos
A vulnerability was identified in DiffSK configobj up to 5.0.9. Affected by this vulnerability is the function _sectionmarker of the file configobj/__init__.py. The manipulation leads to inefficient regular expression complexity. Remote exploitation of the at…
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Medium 6.3
ip-address: Address6 matches a zone identifier in quadratic time ahead of its length limit, allowing a single long string to stall the process
ip-address before 10.7.4 allows a denial of service (CPU consumption from quadratic complexity, and application stall) via many % characters in input reaching a function call that uses the Address6 constructor.
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Medium 5.7
Tandoor Recipes: ReDoS (Regular Expression Denial of Service) via User-Controlled Automation Regex Patterns
Tandoor Recipes is an application for managing recipes, planning meals, and building shopping lists. Prior to 2.6.10, executes user-controlled Automation regular-expression patterns with Python re.sub() without complexity validation or an execution timeout wh…
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Medium 4.9
BottleCRM 0.43 through 1.14.5 ReDoS via Case Routing Rule Regex
BottleCRM 0.43 through 1.14.5 contains a regular expression denial of service vulnerability that allows authenticated organization administrators to block web workers via unbounded routing rule regex patterns. Attackers can create a routing rule with a catast…
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Medium 4.3
Open WebUI 0.11.0 before 0.11.4 ReDoS via grep_knowledge_files Event Loop
Open WebUI from 0.11.0 before 0.11.4 contains a regular expression denial of service vulnerability that allows authenticated users to stall server workers via file search patterns. Attackers can instruct the model to call grep_knowledge_files or grep_chat_fil…
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Medium 6.5
Satel Netco Design Inefficient Regular Expression Complexity
Satel Netco Design versions prior to v2.1.7 contains an inefficient regular expression complexity vulnerability. An authenticated user with Viewer privileges could submit crafted search input that causes excessive processing, potentially degrading the availab…
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Medium 6.5
Pydantic AI: Event loop blocked by quadratic title extraction in `web_fetch`
Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 1.77.0 until 1.107.6 and 2.44.0, the local web_fetch_tool and the WebFetch local fallback process server-controlled responses with quadratic title extract…
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Medium 6.5
Inefficient Regular Expression Complexity in hMailServer
Inefficient complexity in the Sieve filter evaluation of Progressive Robot hMailServer 6.2.24 through 6.3.5 allows an authenticated account holder to make the mail services unavailable with their own filter. A ':matches' pattern was matched by a backtracking …
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Medium 4.3
Twisted: IMAP wildcardToRegexp() ReDoS
Twisted is an event-based framework for internet applications, supporting Python 3.6+. In 25.5.0 and earlier, wildcardToRegexp() in twisted/mail/imap4.py translates the IMAP asterisk and percent wildcards but passes all other characters from an authenticated …
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Medium 4.3
Inefficient Regular Expression Complexity in Elasticsearch Leading to Denial of Service
Inefficient Regular Expression Complexity (CWE-1333) in Elasticsearch can lead to denial of service via Regular Expression Exponential Blowup (CAPEC-492). The ES|QL CHUNK function's recursive chunking strategy accepts a list of user-supplied regular expressio…
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Medium 4.9
Ghost: Regular Expression Denial of Service in Content Import
Ghost is a Node.js content management system. From 4.0.0 until 6.67.0, a crafted content import file could cause excessive CPU usage, making the Ghost server unresponsive. Exploiting this requires Administrator access. This issue is fixed in version 6.67.0.
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Medium 4.9
Ghost: Regular Expression Denial of Service in External Media Inliner
Ghost is a Node.js content management system. From 5.37.0 until 6.67.0, a crafted request to the external media inliner could cause excessive CPU usage, making the Ghost server unresponsive. Exploiting this requires Administrator access. This issue is fixed i…
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Medium 5.3
YesWiki before 4.6.7 ReDoS via wakka.php Edit-Preview Endpoint
YesWiki before 4.6.7 contains an algorithmic-complexity denial of service in the wakka.php formatter due to an O(n^2) markdown-link regex. Unauthenticated attackers can submit a small crafted body of bracket characters to the page-edit preview endpoint to pin…
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Medium 4.0
geopy: Regular Expression Denial of Service (ReDoS) in geopy.Point
geopy is a geocoding library for Python. Prior to 2.5.0, geopy.Point and Point.from_string() can spend excessive CPU time due to inefficient regular-expression behavior when an application passes a long malformed coordinate string without the 256-character in…
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Medium 5.9
In JetBrains YouTrack before 2026.2.19197 reDoS attack was possible via mailbox regex mail-rule filters
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Medium 5.5
Dash: dash: super-polynomial backtracking in pmatch when libc fnmatch is disabled
A flaw was found in dash. When built without libc fnmatch, the internal pmatch() matcher implements * by unbounded recursion over candidate positions. A local user who can plant filenames, or otherwise feed that matcher, can make a short multi-star pattern su…
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Medium 4.4
PyJWT: ReDoS vulnerability when calling the `is_pem_format` function.
PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT is_pem_format is affected because lazy PEM regular expression backtracks extensively. This occurs when a certificate-like input contains repeated BEGIN markers without a matc…
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Medium 6.0
RabbitMQ: Authenticated RabbitMQ JMS Topic Selector Users Can Consume Broker CPU with an Unbounded LIKE Regular Expression
RabbitMQ is a messaging and streaming broker. From 4.0.0 until 4.0.23, 4.1.14, 4.2.9, and 4.3.3, the optional rabbitmq_jms_topic_exchange plugin's x-jms-topic exchange accepted a client-controlled rjms_erlang_selector binding expression whose LIKE evaluator e…
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Medium 6.5
Habitica: Regex Injection / ReDoS in Member Search
Habitica is a habit tracker application that treats goals like a role-playing game. From 4.172.1 until 5.48.2, a query parameter on Habitica's /api/v3/groups/:groupId/members route is not sanitized before being interpreted as a regular expression. An authenti…
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Medium 6.0
RabbitMQ: ReDoS via management API ?name= filter
RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0, match_value/3 passes the user-supplied ?name= regular expression to re:run with no match_limit option, and executes it once per resource in the result s…
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Medium 5.5
JLine: ReDoS via `HISTORY_IGNORE` Configuration Variable
JLine is a Java library for handling console input. From 3.0.0 until 3.30.15 and 4.3.1, DefaultHistory.matchPatterns(String patterns, String line) in reader/src/main/java/org/jline/reader/impl/history/DefaultHistory.java converts the HISTORY_IGNORE configurat…
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Medium 6.5
JLine: ReDoS in Nano Editor Regex Search Mode
JLine is a Java library for handling console input. From 3.0.0 until 3.30.15 and 4.3.1, the JLine built-in nano editor's regex search mode passes a user-controlled search term from doSearch(String text) in builtins/src/main/java/org/jline/builtins/Nano.java t…
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Medium 6.5
Sync-in Server has a ReDoS via Unsanitized Regex in Sync Diff `pathFilters`
Sync-in Server is an open-source platform for file storage, sharing, collaboration, and syncing. Prior to version 2.4.0, the sync diff endpoint compiles a user-supplied string into a `RegExp` with no complexity validation. A catastrophic-backtracking pattern …
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Medium 5.3
Soup Sieve: Polynomial-time ReDoS (O(n²)) in the whitespace/comment trimming regex `RE_WS_END` (triggers on VALID selectors)
Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.9, selector_iter in src/soupsieve/css_parser.py trims the raw selector with RE_WS_END, an end-anchored WSC whitespace-and-comment expression used with search(), so the …
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Medium 5.3
Soup Sieve: Polynomial-time ReDoS (O(n²)) in the `IDENTIFIER` / `VALUE` selector sub-patterns
Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.9, the selector parser in src/soupsieve/css_parser.py defines IDENTIFIER with adjacent quantified groups over overlapping character classes, and VALUE embeds IDENTIFIER…
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Medium 5.3
a2ui-project a2ui Basic Catalog safe_regex.ts redos
A vulnerability was identified in a2ui-project a2ui up to 0.10.6. Affected is an unknown function of the file renderers/web_core/src/v0_9/basic_catalog/functions/safe_regex.ts of the component Basic Catalog. Such manipulation leads to inefficient regular expr…
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Medium 6.5
Apache Artemis, Apache ActiveMQ Artemis: Message selector wildcard handling could lead to denial of service
An authenticated client could attach a consumer with a selector containing crafted wildcard usage that results in excessive evaluation during message delivery attempts, occupying a shared broker thread and leading to denial of service. This issue affects Apac…
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Medium 6.9
Colord: Slow rejection of oversized malformed color strings
Colord is a tiny yet powerful tool for high-performance color manipulations and conversions. Prior to 2.9.4, synchronous CSS color string matchers in src/colorModels/rgbString.ts, src/colorModels/hslString.ts, src/colorModels/hwbString.ts, src/colorModels/lch…