CVE-2026-39315 (GCVE-0-2026-39315)
Vulnerability from cvelistv5
Published
2026-04-09 17:54
Modified
2026-04-13 15:38
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-184 - Incomplete List of Disallowed Inputs
Summary
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.
References
| URL | Tags | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
|||||||||||
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-39315",
"options": [
{
"Exploitation": "poc"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-13T15:28:38.766188Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-13T15:38:52.507Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"references": [
{
"tags": [
"exploit"
],
"url": "https://github.com/unjs/unhead/security/advisories/GHSA-95h2-gj7x-gx9w"
}
],
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "unhead",
"vendor": "unjs",
"versions": [
{
"status": "affected",
"version": "\u003c 2.1.13"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Unhead is a document head and template manager. Prior to 2.1.13, useHeadSafe() is the composable that Nuxt\u0027s own documentation explicitly recommends for rendering user-supplied content in \u003chead\u003e 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(\u0027javascript:\u0027), which does not match. makeTagSafe() writes the raw value directly into SSR HTML output. The browser\u0027s HTML parser decodes the padded entity natively and constructs the blocked URI. This vulnerability is fixed in 2.1.13."
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 6.1,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"privilegesRequired": "NONE",
"scope": "CHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
"version": "3.1"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-184",
"description": "CWE-184: Incomplete List of Disallowed Inputs",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-09T17:54:07.488Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/unjs/unhead/security/advisories/GHSA-95h2-gj7x-gx9w",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/unjs/unhead/security/advisories/GHSA-95h2-gj7x-gx9w"
},
{
"name": "https://github.com/unjs/unhead/commit/961ea781e091853812ffe17f8cda17105d2d2299",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/unjs/unhead/commit/961ea781e091853812ffe17f8cda17105d2d2299"
},
{
"name": "https://github.com/unjs/unhead/releases/tag/v2.1.13",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/unjs/unhead/releases/tag/v2.1.13"
}
],
"source": {
"advisory": "GHSA-95h2-gj7x-gx9w",
"discovery": "UNKNOWN"
},
"title": "Unhead has a hasDangerousProtocol() bypass via leading-zero padded HTML entities in useHeadSafe()"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-39315",
"datePublished": "2026-04-09T17:54:07.488Z",
"dateReserved": "2026-04-06T19:31:07.266Z",
"dateUpdated": "2026-04-13T15:38:52.507Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"vulnrichment": {
"containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-39315\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-04-13T15:28:38.766188Z\"}}}], \"references\": [{\"url\": \"https://github.com/unjs/unhead/security/advisories/GHSA-95h2-gj7x-gx9w\", \"tags\": [\"exploit\"]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-04-13T15:27:54.437Z\"}}], \"cna\": {\"title\": \"Unhead has a hasDangerousProtocol() bypass via leading-zero padded HTML entities in useHeadSafe()\", \"source\": {\"advisory\": \"GHSA-95h2-gj7x-gx9w\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV3_1\": {\"scope\": \"CHANGED\", \"version\": \"3.1\", \"baseScore\": 6.1, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N\", \"integrityImpact\": \"LOW\", \"userInteraction\": \"REQUIRED\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"NONE\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"LOW\"}}], \"affected\": [{\"vendor\": \"unjs\", \"product\": \"unhead\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 2.1.13\"}]}], \"references\": [{\"url\": \"https://github.com/unjs/unhead/security/advisories/GHSA-95h2-gj7x-gx9w\", \"name\": \"https://github.com/unjs/unhead/security/advisories/GHSA-95h2-gj7x-gx9w\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/unjs/unhead/commit/961ea781e091853812ffe17f8cda17105d2d2299\", \"name\": \"https://github.com/unjs/unhead/commit/961ea781e091853812ffe17f8cda17105d2d2299\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/unjs/unhead/releases/tag/v2.1.13\", \"name\": \"https://github.com/unjs/unhead/releases/tag/v2.1.13\", \"tags\": [\"x_refsource_MISC\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"Unhead is a document head and template manager. Prior to 2.1.13, useHeadSafe() is the composable that Nuxt\u0027s own documentation explicitly recommends for rendering user-supplied content in \u003chead\u003e 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(\u0027javascript:\u0027), which does not match. makeTagSafe() writes the raw value directly into SSR HTML output. The browser\u0027s HTML parser decodes the padded entity natively and constructs the blocked URI. This vulnerability is fixed in 2.1.13.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-184\", \"description\": \"CWE-184: Incomplete List of Disallowed Inputs\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-04-09T17:54:07.488Z\"}}}",
"cveMetadata": "{\"cveId\": \"CVE-2026-39315\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-04-13T15:38:52.507Z\", \"dateReserved\": \"2026-04-06T19:31:07.266Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-04-09T17:54:07.488Z\", \"assignerShortName\": \"GitHub_M\"}",
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
Loading…
Loading…