CVE & CISA-KEV Catalog

CVE-2026-31873

UNSCORED

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.

How to fix

Remediation Available
unheadNVD
Affected:< 2.1.11Fixed in:2.1.11CVE-2026-31873derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3.1 Vector

No CVSS vector data available.

Exploit Intelligence

0.24%probability of exploitation in 30 days
15thpercentile

Low risk: more likely to be exploited than 15% of all known CVEs.

References

Exploit1

Related Vulnerabilities

Other CWE-79 (Cross-Site Scripting (XSS)) vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2020-11022Medium6.999%-Fix
CVE-2019-3929Critical9.899%KEVFix
CVE-2020-9496Medium6.199%--
CVE-2023-28341Medium6.199%-Fix
CVE-2018-12998Medium6.198%--
CVE-2025-4123High7.698%-Fix
Embed a live status badge for CVE-2026-31873
CVE-2026-31873 severity badge

Markdown

[![CVE-2026-31873](https://tridentstack.com/cve/badge/CVE-2026-31873.svg)](https://tridentstack.com/cve/CVE-2026-31873)

HTML

<a href="https://tridentstack.com/cve/CVE-2026-31873"><img src="https://tridentstack.com/cve/badge/CVE-2026-31873.svg" alt="CVE-2026-31873"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-03-16.