PostCSS Selector Parser is a CSS selector parser that integrates with PostCSS but does not require it. Prior to 7.1.6, src/parser.js splitWord() can receive a flat selector as one word token carrying many class or ID indexes because period and hash characters are not tokenizer word delimiters. The uniqs() deduplication and per-index class and ID membership checks repeatedly scan the class and ID index arrays, while a separate Sass-interpolation filtering pass also performs repeated linear scanning. Together, these passes make parsing quadratic in the number of indexes and allow a crafted selector to occupy a synchronous parser thread. The maxNestingDepth guard does not mitigate the issue because the hostile selector can have zero nesting depth. Only consumers that synchronously parse untrusted selectors in an exposed request path are affected; ordinary build-time parsing of trusted sources is not affected. This issue is fixed in version 7.1.6.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - PostCSS Selector Parser is a CSS selector parser that integrates with PostCSS but does not require it.
    Prior to 7.1.6, src/parser.js splitWord() can receive a flat selector as one word token carrying many
    class or ID indexes because period and hash characters are not tokenizer word delimiters. The uniqs()
    deduplication and per-index class and ID membership checks repeatedly scan the class and ID index arrays,
    while a separate Sass-interpolation filtering pass also performs repeated linear scanning. Together, these
    passes make parsing quadratic in the number of indexes and allow a crafted selector to occupy a
    synchronous parser thread. The maxNestingDepth guard does not mitigate the issue because the hostile
    selector can have zero nesting depth. Only consumers that synchronously parse untrusted selectors in an
    exposed request path are affected; ordinary build-time parsing of trusted sources is not affected. This
    issue is fixed in version 7.1.6. (CVE-2026-104844)

ID	Name	Product	Family	Type	Severity
473578	Echo: postcss-selector-parser: security update to 7.1.6	Tenable Cloud Security	Echo Local Security Checks	Local	medium
473578	Echo: postcss-selector-parser: security update to 7.1.6	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	medium
473024	SCA: security update for postcss-selector-parser (GHSA-rj75-hqrm-r3gf)	Tenable Cloud Security	SCA Checks	Local	medium
473024	SCA: security update for postcss-selector-parser (GHSA-rj75-hqrm-r3gf)	Tenable Self-Hosted Container Security	SCA Checks	Local	medium

Detections

Analytics

CVE-2026-104844

medium

Tenable Plugins

medium

medium

medium

medium