{"id":"CVE-2026-73646","sourceIdentifier":"security-advisories@github.com","published":"2026-08-17T16:17:47.257","lastModified":"2026-09-18T20:05:53.723","vulnStatus":"Awaiting Analysis","cveTags":[],"descriptions":[{"lang":"en","value":"PostCSS takes a CSS file and provides an API to analyze and modify its rules by transforming the rules into an Abstract Syntax Tree. Prior to 8.5.18, lib/previous-map.js loadMap() passes attacker-controlled sourceMappingURL values to join(dirname(opts.from), annotation), and loadFile() permits traversed or absolute .map paths, allowing untrusted CSS processed without map: false to disclose sourcesContent from arbitrary reachable .map files through result.map. This issue is fixed in version 8.5.18."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"postcss","product":"postcss","versions":[{"version":"< 8.5.18","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"NONE","availabilityImpact":"NONE"},"exploitabilityScore":3.9,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-08-17T16:35:17.036116Z","id":"CVE-2026-73646","options":[{"exploitation":"poc"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-22"}]}],"references":[{"url":"https://github.com/postcss/postcss/commit/95663d3eb7ba26f4854dd19d3b4f4425760cf56c","source":"security-advisories@github.com"},{"url":"https://github.com/postcss/postcss/releases/tag/8.5.18","source":"security-advisories@github.com"},{"url":"https://github.com/postcss/postcss/security/advisories/GHSA-r28c-9q8g-f849","source":"security-advisories@github.com"},{"url":"https://github.com/postcss/postcss/security/advisories/GHSA-r28c-9q8g-f849","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}]}