Bug 2501922 (CVE-2026-53727) - CVE-2026-53727 css_parser: css_parser: Arbitrary local file disclosure via Server-Side Request Forgery
Summary: CVE-2026-53727 css_parser: css_parser: Arbitrary local file disclosure via Se...
Keywords:
Status: NEW
Alias: CVE-2026-53727
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-07-17 21:01 UTC by OSIDB Bzimport
Modified: 2026-07-21 01:47 UTC (History)
6 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-07-17 21:01:41 UTC
css_parser is a Ruby CSS parser. From 2.2.0 until 3.0.0, CssParser::Parser#read_remote_file in lib/css_parser/parser.rb, and therefore load_uri! and the @import-following branch of add_block!, issued HTTP and HTTPS requests against any host, port, and URI without a scheme allowlist, host or IP filtering, or protection against link-local, loopback, or RFC-1918 addresses. Location: redirects were followed recursively back into the same function, which also serviced file:// URIs, so a single attacker-controlled HTTP redirect could upgrade the bug from SSRF to arbitrary local file disclosure. Any consumer of css_parser that hands it attacker-influenced CSS together with a base_uri: option is exposed. This issue is fixed in version 3.0.0.


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