CVE-2026-50290
CVE-2026-50290 · @asymmetric-effort/specifyjs: CSS expression sanitization is bypassable in renderToString
This page contains facts from public vulnerability sources. Check the original advisory before updating.
SpecifyJS is a declarative TypeScript user interface framework. Prior to version 0.2.136, CSS value sanitization stripped `expression(` and `url(javascript:` using simple regex, but could be bypassed with CSS unicode escapes (`\65xpression(`), null bytes, or CSS comments (`exp/**/ression(`). These CSS injection vectors only work in legacy browsers (IE6-IE10). SpecifyJS targets modern browsers. Starting in version 0.2.136, CSS sanitization now normalizes unicode escapes and strips CSS comments before pattern matching. Also checks for `behavior:`, `-moz-binding`, and `-o-link` patterns.
CVSS 5.3 · Medium · EPSS 0.5% · Fix available
- Published
- Updated
Stack: node
Affected products and versions
specifyjs
- Versions
- < 0.2.136: Affected
No fix published
@asymmetric-effort/specifyjs npm
- Affected ranges
- SEMVER: < 0.2.136
Update to 0.2.136