CVE-2026-53727
Review this vulnerability's source-backed evidence, with unavailable values and read failures kept distinct.
A permanent, source-backed tracker page. Values are shown only when returned; explicit gaps and read failures remain different states.
Detection and validation
Mapped metadata availability only. These signals do not change priority.
Sigma
Not mapped by tracked sources.
Atomic
Not mapped by tracked sources.
Nuclei
Not mapped by tracked sources.
What it is
Reportedcss_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.…
Source reported · Source: NVD · Source last published: · Source description excerpt; complete tracked detail loads below. · Source last updated: · Tracker data as of:
What is affected
Reportedpremailer; CSS Parser. Product-level identification only; no affected-version conclusion is available from this field.
Source reported · Source: NVD · Source last published: · Source last updated: · Tracker data as of:
Urgency and basis
ReportedTrack* · 230.3
Tracker computed · Tracker decision tier from the evidence detailed below · Source last updated: · Tracker data as of:
Exploitation evidence
Not reportedNot reported by tracked sources.
What to do
ReportedA source remediation link is available. Validate that guidance against the affected product and your environment.
Source remediation ↗Source reported · Tracked source remediation field · Source last updated: · Tracker data as of:
Evidence detail
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