CVE-2026-69153
Prior to 8.5.19, if from is unset, an attacker can cause PreviousMap.loadFile() to read an unintended source-map file by supplying an absolute or directory-traversal sourceMappingURL.
Does this matter?
Lower severity and a low EPSS score (0.45%). Track it; it rarely justifies an emergency change on its own.
Description
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 8.5.19, if from is unset, an attacker can cause PreviousMap.loadFile() to read an unintended source-map file by supplying an absolute or directory-traversal sourceMappingURL. The resulting map’s sources and sourcesContent may then be exposed to the application. This issue is fixed in version 8.5.19.
- CVSS 4.0
- 6.3 MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.45% probability · 38th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-22, CWE-200
- Affected
- postcss/postcss
- Source
- security-advisories@github.com
References
- https://github.com/postcss/postcss/commit/7beca139e70f9075c6b19700fcb00dd8033e5da8Patch
- https://github.com/postcss/postcss/releases/tag/8.5.19Product, Release Notes
- https://github.com/postcss/postcss/security/advisories/GHSA-fxqj-rqcc-2cmpExploit, Mitigation, Vendor Advisory
- https://github.com/postcss/postcss/security/advisories/GHSA-fxqj-rqcc-2cmpExploit, Mitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.