Vulnerability record

CVE-2026-45623

A permanent, source-backed tracker page. Values are shown only when returned; explicit gaps and read failures remain different states.

Full record read. Reported values and explicit gaps below come from the tracked record. Tracker snapshot: Aug 8, 2026.

What it is

Reported

PostCSS takes a CSS file and provides an API to analyze and modify its rules by transforming the rules into an Abstract Syntax Tree. In versions 8.5.11 and prior, the PreviousMap parses the /*# sourceMappingURL=PATH */ comment from any CSS string passed to process() and dereferences PATH against the local filesystem with no scheme, allowlist, or traversal check. An attacker who controls the CSS input can cause the host process to read any file readable by Node and leak the first ~10 bytes of its content through the resulting JSON.parse SyntaxError message.… Source description excerpt; complete tracked detail loads below.

NVD published: Jul 27, 2026 · Source record updated: Aug 8, 2026 · Tracker snapshot: Aug 8, 2026

What is affected

Reported

postcss — PostCSS. Product-level identification only; no affected-version conclusion is available from this field.

NVD published: Jul 27, 2026 · Source record updated: Aug 8, 2026 · Tracker snapshot: Aug 8, 2026

Urgency and basis

Reported

Track* · 228.9

Tracker decision tier from the evidence detailed below · Source record updated: Aug 8, 2026 · Tracker snapshot: Aug 8, 2026

Exploitation evidence

Not reported

Not reported by tracked sources.

What to do

Reported

A source remediation link is available. Validate that guidance against the affected product and your environment.

Source remediation ↗

Tracked source remediation field · Source record updated: Aug 8, 2026 · Tracker snapshot: Aug 8, 2026

Evidence detail

Loading the full tracker evidence record…