CVE-2026-31873

N/A NONE
Published: March 12, 2026 Modified: March 16, 2026
View on NVD

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/unjs/unhead/security/advisories/GHSA-5339-hvwr-7582
Source: security-advisories@github.com
Exploit Mitigation Vendor Advisory

1 reference(s) from NVD

Quick Stats

CVSS v3 Score
N/A / 10.0
EPSS (Exploit Probability)
0.0%
10th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

unjs