MEDIUM · CVSS 5.3

CVE-2023-44270 — PostCSS newline parsing bypass

A newline-parsing issue in PostCSS could let attacker-controlled CSS bypass sanitization, potentially enabling CSS-injection attacks in applications that accepted user CSS.

Affects
  • postcss < 8.4.31

What an attacker does

Apps that accept user-supplied CSS (themes, rich-text editors with CSS rules) passed input through PostCSS for validation. The newline-parsing bug let crafted CSS survive sanitization with executable-payload metadata intact.

How to detect

`npm ls postcss`.

How to fix

Upgrade PostCSS to 8.4.31+ (pulled transitively by Tailwind CSS 3.4.0+).

Securie findingmedium · CVSS 5.3
CVE-2023-44270

How Securie catches CVE-2023-44270

Securie checks PostCSS version behind Tailwind and other build pipelines.

Scan my repo for CVE-2023-44270 →Securie reviews every PR · proves real issues · opens verified fix PRs

References