CVE Catalog

CVE-2026-53727

HighCVSS 8.6
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.30%

23th percentile - higher than 23% of all known CVEs

Summary

SSRF vulnerability in the Ruby css_parser library versions 2.2.0 through 3.0.0. The read_remote_file method makes HTTP/HTTPS requests to any host without filtering, and redirects can lead to local file disclosure via file:// URIs.

Risk Assessment

An attacker can use this vulnerability to scan internal networks, read sensitive files on the server, or attack other systems.

Recommendation

Update the css_parser library to version 3.0.0, which contains the fix.

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS