CWE-1333Base

Inefficient Regular Expression Complexity

Draft in the CWE catalog · 350 CVEs mapped

350
CVEs mapped
6.5
Median CVSS
What it is

The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.

Recent examples
none
CVE-2026-85062

CVE-2026-85062 - UNKNOWN Severity Vulnerability

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/lchString.ts, and src/colorModels/cmykString.ts use the ambiguous numeric regular expression ([+-]?\d*.?\d+), allowing the same digits to be divided between overlapping quantifiers in quadratically many ways when malformed input is rejected. An attacker who can supply an unbounded color string to colord(), getFormat(), isEqual(), mix(), or contrast(), including through a request body, JSON field, or uploaded stylesheet, can block the processing thread with a multi-kilobyte payload. The affected matchers are parseRgbaString, parseHslaString, parseHwbaString, parseLchaString, and parseCmykaString. This issue is fixed in version 2.9.4.

no explanation yet
0%
epss
7.5cvss
CVE-2026-84642

CVE-2026-84642 - HIGH Severity Vulnerability

The values of the mail.allowed_attachment_hostnames advanced config setting were used in a regular expression without escaping. For some possible valid hostnames, this could allow certain unintended hostnames to also match and serve remote attachments. This vulnerability was fixed in Thunderbird 155 and Thunderbird 153.2.

HIGHno explanation yet
0%
epss
none
CVE-2026-83619

CVE-2026-83619 - UNKNOWN Severity Vulnerability

xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. From 0.7.0 until 0.8.15, the release-0.8.x parser in lib/sax.js trims captured end-tag names with the unanchored global expression /[ \t\n\r]+$/g. For an end tag containing a long whitespace run followed by a non-whitespace character, the expression retries from each possible starting position and backtracks quadratically before failing its end anchor. DOMParser.parseFromString() reaches the path under default options, allowing a small unauthenticated XML input to stall the Node.js event loop; the 0.9.x and unscoped npm lines do not contain this expression. This issue is fixed in @xmldom/xmldom version 0.8.15.

no explanation yet
0%
epss
The record
Technical detail
CWE ID
CWE-1333
Abstraction
Base
Structure
Simple
Status
Draft
References (7)