6.1

CVE-2026-39315

Exploit

Unhead has a hasDangerousProtocol() bypass via leading-zero padded HTML entities in useHeadSafe()

Unhead is a document head and template manager. Prior to 2.1.13, useHeadSafe() is the composable that Nuxt's own documentation explicitly recommends for rendering user-supplied content in <head> safely. Internally, the hasDangerousProtocol() function in packages/unhead/src/plugins/safe.ts decodes HTML entities before checking for blocked URI schemes (javascript:, data:, vbscript:). The decoder uses two regular expressions with fixed-width digit caps. The HTML5 specification imposes no limit on leading zeros in numeric character references. When a padded entity exceeds the regex digit cap, the decoder silently skips it. The undecoded string is then passed to startsWith('javascript:'), which does not match. makeTagSafe() writes the raw value directly into SSR HTML output. The browser's HTML parser decodes the padded entity natively and constructs the blocked URI. This vulnerability is fixed in 2.1.13.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Unjs ≫ Unhead SwPlatformnode.js Version < 2.1.13
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.29% 0.2
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
security-advisories@github.com 6.1 2.8 2.7
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CWE-184 Incomplete List of Disallowed Inputs

The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are not allowed by policy or otherwise require other action to neutralize before additional processing takes place, but the list is incomplete.

https://github.com/unjs/unhead/commit/961ea781e091853812ffe17f8cda17105d2d2299
Patch
https://github.com/unjs/unhead/releases/tag/v2.1.13
Product
Release Notes
https://github.com/unjs/unhead/security/advisories/GHSA-95h2-gj7x-gx9w
Vendor Advisory
Exploit
Mitigation