CVE-2026-31873

MEDIUM EPSS 14.6%
Published Mar 12, 20263mo ago · Modified Jun 17, 20262w ago
6.1 CVSS 3.1
Medium
Find Similar
Published Mar 12, 2026 3mo ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
6.1
Exploitability
2.8
Impact
2.7
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction Required
Scope Changed
Confidentiality Low
Integrity Low
Availability None

Threat Intelligence

EPSS Exploit Probability
14.6% percentile
Exploit & Patch Status
Public Exploit Known
No Patch Available

Weaknesses 1

CWE-79 Cross-site Scripting Injection

Affected Products 1

VendorProductVersionRange
unjsunhead* <2.1.11

References 1

  • github.com https://github.com/unjs/unhead/security/advisories/GHSA-5339-hvwr-7582
    ExploitMitigationVendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.