CVE-2026-31873
Unhead has a Bypass of URI Scheme Sanitization in makeTagSafe via Case-Sensitivity
- State
- Published
- Severity
- 0.0 None
- Published
- Mar 12, 2026
- Updated
- Mar 12, 2026
- Reserved
- Mar 9, 2026
Description
Unhead is a document head and template manager. Prior to 2.1.11, The link.href check in makeTagSafe (safe.ts) uses String.includes(), which is case-sensitive. Browsers treat URI schemes case-insensitively. DATA:text/css,... is the same as data:text/css,... to the browser, but 'DATA:...'.includes('data:') returns false. An attacker can inject arbitrary CSS for UI redressing or data exfiltration via CSS attribute selectors with background-image callbacks. This vulnerability is fixed in 2.1.11.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 0.0 None | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N | GitHub_M |
Weaknesses
- CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Products
| Product | Versions |
|---|---|
unheadunjs |
|
References
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