CWE-1333
A regular expression blows up on a chosen input and stalls processing (ReDoS).
- 16
- vulnerabilities tracked
- 17 July 2026
- latest publication
cve
Vulnerability watch
idvulnerabilityseveritypublished
CVE-2026-14741HTTP::Date versions before 6.08 for Perl allow CPU exhaustion via polynomial regex backtracking in parse_date.
parse_date() matches the date string against a chain of alternative regexes, and str2time() delegates to it. Several of these patterns place unbounded quantifiers next to each other before a trailing `\s*$` anchor. A valid date prefix followed by a long interior run of digits, letters, or whitespace and a single trailing byte that defeats the final match forces the engine to repartition the run, giving polynomial (about quadratic) backtracking. A header value of a few tens of kilobytes runs for tens of seconds of CPU.
HTTP::Date parses timestamps such as HTTP `Date`, `Expires`, and `Last-Modified` headers, which commonly originate from untrusted sources. Any caller that passes an untrusted date header to str2time() or parse_date() can be driven to consume unbounded CPU, a denial of service. High CVSS 7.5 CVE-2026-49485HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to 6.9.9 and 6.9.4.2, all implementations of FHIRPathEngine accept arbitrary FHIRPath expressions and evaluate them without input validation, and the FHIRPath functions matches(), matchesFull(), and replaceMatches() pass user-controlled regular expressions to Java's Pattern.compile() and String.replaceAll() through an incomplete timeout utility. An attacker can send a resource containing an evil regex pattern that causes catastrophic backtracking, exhausting CPU resources and causing denial of service in the FHIR Validator HTTP endpoint and affected org.hl7.fhir.* modules. This issue is fixed in versions 6.9.9 and 6.9.4.2.NVD analysis in progress High CVSS 7.5 CVE-2026-52746JSONata is a JSON query and transformation language. Prior to 2.2.0, malicious non-matching inputs to the $toMillis function can cause superlinear backtracking in the ISO-8601 validation regex, leading to denial of service in applications that evaluate user-provided JSONata expressions. This issue is fixed in version 2.2.0.NVD analysis in progress High CVSS 7.5 CVE-2026-45367HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to 6.9.7, the FHIRPathEngine implementation passes user-controlled regular expressions from matches(), matchesFull(), and replaceMatches() to Java regex operations without effective timeouts, allowing catastrophic backtracking and denial of service. This issue is fixed in version 6.9.7.NVD analysis in progress High CVSS 7.5 CVE-2026-45133Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, when the parser is exposed to attacker-controlled input, deeply nested mappings or sequences cause both the block-level (Parser::parseBlock()) and inline (Inline::parseSequence() / Inline::parseMapping()) parsers to recurse without a depth limit. A crafted document exhausts the PHP stack and crashes the worker. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.Sensiolabs Symfony High CVSS 7.5 CVE-2026-45305Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, Symfony\Component\Yaml\Parser::cleanup() used regular expressions with overlapping quantifiers for YAML directive, comment, and document marker cleanup, allowing crafted input to make parsing hang for an arbitrarily long time. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.Sensiolabs Symfony High CVSS 7.5 CVE-2026-45756Symfony is a PHP framework for web and console applications and a set of reusable PHP components. From 7.3.0-BETA1 until 7.4.12 and 8.0.12, the JsonPath component compiles attacker-controlled match() and search() filter patterns directly into preg_match() without a length cap, i-regexp restriction, or bounded backtracking, allowing catastrophic-backtracking expressions to pin worker CPU and cause denial of service. This issue is fixed in versions 7.4.12 and 8.0.12.Sensiolabs Symfony High CVSS 7.5 CVE-2026-48801linkify-it is a links recognition library with full Unicode support. Prior to 5.0.1, LinkifyIt.prototype.match, the package's primary public API, has O(N²) algorithmic complexity for inputs containing many fuzzy links or emails because the JavaScript-level scan loop re-slices input and re-runs unanchored regex searches on progressively shorter tails. Any service that synchronously renders untrusted Markdown with linkify:true on a request hot path can inherit a worker-process denial of service triggerable by a tens-of-KB request body. This issue is fixed in version 5.0.1.NVD analysis in progress High CVSS 8.7 CVE-2026-49477Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.8.4, the CSS selector parser in soupsieve contains a regular expression vulnerable to catastrophic backtracking when processing an attribute selector with an unterminated quoted value in soupsieve/css_parser.py, allowing an attacker who can supply untrusted CSS selector strings to soupsieve.compile() or Beautiful Soup .select() / .select_one() to cause CPU exhaustion and denial of service. This issue is fixed in version 2.8.4.NVD analysis in progress High CVSS 7.5 CVE-2026-57584Phalcon is a high-performance, full-stack PHP framework. Prior to 5.15.0, every Phalcon MVC application built with a default router registers a built-in route whose compiled PCRE pattern contains the nested quantifier (/.), and the same construct is produced by the /:params placeholder and the CLI router. Phalcon\Mvc\Router::handle() matches this pattern against the attacker-controlled request URI on every request, so a crafted path such as one containing repeated slashes followed by decoded newlines can trigger catastrophic backtracking and cause CPU exhaustion or route-matching failure. This issue is fixed in version 5.15.0. High CVSS 8.7 CVE-2026-55470HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to 6.9.10, the fix for CVE-2026-45367 incompletely patched the DSTU2 module, leaving FHIRPathEngine.matches() in org.hl7.fhir.dstu2/utils/FHIRPathEngine.java to call raw String.matches(sw) without RegexTimeout protection while replaceMatches() was updated, allowing an unauthenticated attacker to trigger catastrophic regex backtracking and exhaust server CPU. This issue is fixed in version 6.9.10.Hapifhir Hl7 Fhir Core High CVSS 7.5 CVE-2026-59922Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a run of closed tilde, equals-sign, or caret marker pairs around a character causes quadratic work in src/mistune/plugins/formatting.py when the strikethrough, mark, or insert plugin scans for matching markers from each possible start position, allowing denial of service through CPU exhaustion. This issue is fixed in version 3.3.0.Mistune Project Mistune High CVSS 7.5 CVE-2026-59925Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, long sequences of well-formed double-asterisk or triple-asterisk emphasis pairs around a character cause quadratic work in src/mistune/inline_parser.py because the parser scans forward for matching close markers from every potential opening run, allowing denial of service in default Mistune parsing. This issue is fixed in version 3.3.0.Mistune Project Mistune High CVSS 7.5 CVE-2026-59928Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a Markdown document containing many repeated or distinct reference-link definitions causes quadratic work in src/mistune/block_parser.py and the ref_links environment dictionary handling, allowing denial of service through CPU exhaustion. This issue is fixed in version 3.3.0.Mistune Project Mistune High CVSS 7.5 CVE-2026-14895String::Util versions before 1.36 for Perl are susceptible to a regular expression denial of service.
The trim and rtrim functions stripped trailing whitespace with s/\s*$//u. Because \s* matches greedily and the $ anchor fails whenever a non-whitespace character follows the whitespace, the regex engine retries the match at each offset of a long whitespace run, producing quadratic backtracking. The fix replaces \s*$ with \s+$.
Any caller that passes untrusted input to trim or rtrim can trigger CPU exhaustion with a string containing a long run of whitespace. High CVSS 7.5 CVE-2026-55574vLLM is a high-throughput and memory-efficient inference and serving engine for LLMs. Prior to 0.24.0, the structured_outputs.regex API parameter passes a user-supplied regular expression string directly to the grammar compiler backends with no compilation timeout; in the xgrammar backend the string reaches the regex compiler with no guard, and in the outlines backend the validation step blocks structural issues such as lookarounds and backreferences but performs no complexity analysis, so a pattern with nested quantifiers passes all checks and causes exponential state-space expansion, allowing a single request containing an adversarial regex to hang an inference worker indefinitely and deny service. This issue is fixed in version 0.24.0.Vllm High CVSS 7.5