CVE-2026-39315

MEDIUM

6.1

Description

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.

Details CVE

Score CVSS v3.16.1

SeveriteMEDIUM

Vecteur CVSSCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Vecteur d'attaqueNETWORK

ComplexiteLOW

Privileges requisNONE

Interaction utilisateurREQUIRED

Publie4/9/2026

Derniere modification4/9/2026

Sourcenvd

Observations honeypot0

Faiblesses (CWE)

CWE-184

References

https://github.com/unjs/unhead/commit/961ea781e091853812ffe17f8cda17105d2d2299(security-advisories@github.com)

https://github.com/unjs/unhead/releases/tag/v2.1.13(security-advisories@github.com)

https://github.com/unjs/unhead/security/advisories/GHSA-95h2-gj7x-gx9w(security-advisories@github.com)

Correlations IOC

Aucune correlation enregistree

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