CVE-2026-39315
Unhead is a document head and template manager.
Published Apr 9, 2026 · updated Jun 17, 2026 · unjs unhead
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 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.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Apr 9, 2026 · NIST NVD
Detected
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 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 r
Jun 17, 2026 · NIST NVD
Updated
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 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 r
Affected
- cpe unjs/unheadversion unspecified
Sources
- CVE.orgVulnerability recordCVE-2026-39315
Official CVE identifier
cve.org - NIST NVDVulnerability recordCVE-2026-39315
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 safely. Internally, the hasDangerousProtocol() function in packages/unhead/src/plugin
nvd.nist.gov