CVE-2026-116695
Crass: Incorrect tokenization of bad URLs enables CSS sanitizer bypass
- State
- Published
- Severity
- 5.3 Medium
- Published
- Oct 27, 2026
- Updated
- Oct 27, 2026
- Reserved
- Oct 26, 2026
Description
Crass is a Ruby CSS parser that is compliant with the CSS Syntax Level 3 specification. Prior to 1.0.8, Crass incorrectly treats a closing parenthesis after an escaped backslash as escaped while consuming the remnants of a bad URL. Crass therefore keeps declarations, style rules, or at-rules inside a bad URL token even though a browser treats them as live CSS. A sanitizer that parses untrusted CSS with Crass and reserializes it without rejecting the bad URL can allow CSS used for UI redress, external resource loading, or CSS-based data exfiltration, but this issue does not enable script execution in modern browsers. This issue is fixed in version 1.0.8.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 5.3 Medium | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N | GitHub_M |
Weaknesses
- CWE-436 Interpretation Conflict
Affected Products
| Product | Versions |
|---|---|
crassrgrove |
|
References
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