Inefficient Regular Expression Complexity

@hapi/content from 6.0.1 before 6.0.3 contains a regular expression denial of service vulnerability in Content.disposition() caused by an incomplete fix for CVE-2026-35213. Unauthenticated remote attackers can send multipart uploads with a long Content-Disposition parameter lacking an equals sign, triggering quadratic backtracking that blocks the event loop.Show less

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-backtracking patterns via RegexExtractionStrategy.custom, RegexChunking.patterns or JsonCss, JsonXPath and JsonLxml schema regex fields against a crafted page to freeze the entire server, including /health.Show less

Mistune from 3.0.0 before 3.3.0 contains an algorithmic complexity denial of service vulnerability in the parse_link_text function in src/mistune/helpers.py. Attackers can submit markdown with deeply nested square brackets triggering quadratic parsing time, exhausting server CPU with small crafted requests.Show less

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 headers with an unbounded optional-whitespace regular expression. A malformed header containing a long run of spaces or tabs without a following comma causes quadratic backtracking before the member-count limit is applied. Services using the default W3C Trace Context propagator can therefore spend excessive CPU time on one unauthenticated request when the HTTP server, parser, gateway, or custom carrier accepts a sufficiently large header. The processing can occupy a synchronous worker or delay unrelated requests on the same asynchronous event loop. The impact is limited to availability and does not expose or modify telemetry data or allow code execution. This issue is fixed in version 1.45.1.Show less

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 backtracking expression to the attacker-controlled header before image dimensions are accepted, stalling a worker for minutes and denying service. This issue is fixed in version 13.0.0.Show less

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 attack is possible. The project was informed of the problem early through an issue report but has not responded yet.Show less

Picomatch through 4.0.7 contains a regular expression denial of service vulnerability that allows attackers to block the event loop by supplying single-branch repeated extglob patterns. Attackers can provide globs like +(*) or +(*a), which analyzeRepeatedExtglob in lib/parse.js skips, causing exponential backtracking against short crafted strings and denying service to Node.js applications.Show less

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 when an authenticated user stores a catastrophic-backtracking regex and any user in the same Space imports a matching recipe. Request processing uses Automation.param_2, apply_regex_replace_automation, sub, api/recipe-from-source/. The attack works because the shared-Space automation engine evaluates the malicious pattern during recipe import and can occupy a Gunicorn worker until its request timeout. This can exhaust application worker slots and make the service unavailable to users. This issue is fixed in version 2.6.10.Show less

tarteaucitron.js before 1.37.0 contains a regular expression denial of service vulnerability that allows attackers to block visitor pages by supplying unescaped cookie names to cookie.purge. Attackers can plant a cookie from a sibling subdomain or inject a purgeBtn element with a catastrophic-backtracking data-cookie pattern that freezes the page when the purge button is clicked.Show less

AdonisJS HTTP Server is a package for handling HTTP requests in the AdonisJS framework. Prior to 8.2.2 and 9.1.1, the regular expression returned by router.matchers.slug() contains adjacent greedy repetitions with overlapping character classes. When an application applies this matcher to an attacker-controlled route parameter, a long slug ending in a character rejected by the final assertion causes quadratic backtracking and excessive CPU use. Route matching occurs before route and group middleware, so authentication or rate-limiting middleware attached to the route may not prevent an unauthenticated request from blocking the Node.js event loop and stopping the worker from serving unrelated requests or health checks. This issue is fixed in versions 8.2.2 and 9.1.1.Show less

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to versions 5.4.54, 6.4.46, 7.4.19, and 8.1.7, HeaderUtils::split() parsed header values with a pattern whose token alternative also matched whitespace, followed by a (?<!\s) lookbehind. A run of whitespace placed before a separator could be divided among the iterations of the enclosing repetition in exponentially many ways, and the engine tried all of them before settling. HeaderBag calls it for the Cache-Control header whenever a Request is built, so any application handling HTTP requests is reachable, with no authentication. A single request carrying such a header costs close to a second of CPU (813 ms for a run of 17 spaces in an 8 KB header on PHP 8.5, doubling with each extra space). From 18 spaces on, preg_match_all() gives up at pcre.backtrack_limit and split() returns an empty array, so every directive of the header is silently dropped. This issue affects symfony/http-foundation v4.1.0-BETA1 through v5.4.53, v6.0.0-BETA1 through v6.4.45, v7.0.0-BETA1 through v7.4.18, and v8.0.0-BETA1 through v8.1.6.Show less

Nodemailer 3.0.0 before 10.0.13 has a regular expression denial of service in SMTPConnection._actionEHLO, whose four AUTH mechanism detection regexes contain overlapping whitespace sub-patterns that backtrack quadratically. A malicious or man-in-the-middle SMTP server can reply to EHLO with 250-AUTH, a long whitespace run and a non-matching token, blocking the Node.js event loop for tens of seconds to hours before authentication.Show less

GitPython before 3.2.0 contains a regular expression denial of service vulnerability in the _re_actor_epoch pattern used by parse_actor_and_date on author, committer, and tagger lines. Attackers can serve repositories with commit or tag objects containing long space-filled lines lacking a valid epoch or timezone, causing quadratic backtracking and CPU exhaustion.Show less

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 catastrophically backtracking pattern evaluated by _match_condition() during case saves, exhausting workers shared across all tenants.Show less

N3.js before 2.11.1 contains a regular expression denial of service vulnerability in the N3Lexer number pattern that backtracks quadratically on long digit runs. Attackers can supply untrusted Turtle or N3 input containing long runs of digits that do not end a number, blocking the Node.js event loop and causing denial of service.Show less

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_files with a catastrophically backtracking regex, blocking the event loop for two seconds per repeated call.Show less

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 availability of the application.Show less

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 extraction, whitespace normalization, and ordered-list numbering. An attacker-controlled page of modest size can therefore block the event loop for an extended period, stalling other agent runs and requests, while unsupported codecs or excessive HTML or JSON nesting can abort an individual run. This issue is fixed in versions 1.107.6 and 2.44.0.Show less

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 descent whose time grew with the matched value's length raised to the number of wildcards, so a pattern such as '*a*a*a*b' over 800 characters took 44 seconds; and 'deleteheader' erased the fields it removed one at a time, so removing many fields of one name over a message's header cost O(N^2) (80,000 fields took 18.8 seconds). Sieve filters run on the small, shared delivery thread pool, so an account holder whose active script does this, fed a few messages they can send themselves, empties the pool and stops delivery for the whole server. The script is the account holder's own and cannot be set for another user.Show less