CVE-2026-53727
HIGH
MEDIUM
Priority: 0.04
BB Relevance:
78/100
Published: 2026-07-17
Modified: 2026-10-24
First seen: 2026-10-29
Status: active
Attack Surface
Network
Low Complexity
No Auth
No Interaction
Conf. Impact
CVSS Vector Breakdown
AV:
Network
AC:
Low
PR:
None
UI:
None
S:
X
AT:
Present
VC:
High
VI:
None
VA:
None
Description
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.
Weakness Classification (1)
Affected Software (1)
| Vendor | Product | Version |
|---|---|---|
| premailer | css_parser | 2.2.0 |
References & Advisories (4)
Product
Patch
Patch
Exploit
Mitigation
Vendor Advisory