Ruby CSS Parser: SSRF and Local File Disclosure in `CssParser::Parser#read_remote_file`

Date Jul 9, 2026
Type Vendor advisory
Signal High-risk advisory
Vendor / Product RubyGems ยท css_parser
CVE CVE-2026-53727
High-risk advisory CVE-2026-53727

Summary

Ruby CSS Parser: SSRF and Local File Disclosure in `CssParser::Parser#read_remote_file`

Why it matters

GitHub has published a reviewed security advisory for css_parser. Prioritize it with other application dependency updates.

Operator check

Check whether css_parser is present in application dependency manifests, lockfiles, or build images. Review the GitHub advisory and upgrade to a patched version where available. CVSS score: 8.9.

Sources

PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.