Medium
node-postcss — security advisory
PostCSS takes a CSS file and provides an API to analyze and modify its rules by transforming the rules into an Abstract Syntax Tree. Versions prior to 8.5.10 do not escape `` sequences when stringifying CSS ASTs. When user-submitted CSS is parsed and re-stringified for embedding in HTML `` in CSS values breaks out of the style context, enabling XSS. Version 8.5.10 fixes the issue.
- Products
- node-postcss
- Affected versions
- 6.0.23-1, 6.0.23-3, 8.2.1+~cs5.3.23-8, 8.4.20+~cs8.0.23-1, 8.4.31+~cs8.0.26-1, 8.4.49+~cs9.2.32-1, 8.4.5+~cs7.1.51-2, 8.4.6+~cs7.3.21-1, 8.5.15+~cs9.3.34-1, 8.5.15+~cs9.3.38-1, 8.5.15+~cs9.3.39-1build1, 8.5.25+~cs10.2.23-1, 8.5.26+~cs10.2.24-1, 8.5.6+~cs9.3.28-1, 8.5.8+~cs9.3.30-1
- Fixed versions
- Not specified
- CVEs
- CVE-2026-41305
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 02:10 UTC · Revision 1
Source evidence
PostCSS takes a CSS file and provides an API to analyze and modify its rules by transforming the rules into an Abstract Syntax Tree. Versions prior to 8.5.10 do not escape `` sequences when stringifying CSS ASTs. When user-submitted CSS is parsed and re-stringified for embedding in HTML `` in CSS values breaks out of the style context, enabling XSS. Version 8.5.10 fixes the issue.
osv:UBUNTU-CVE-2026-41305
node-postcss
Fixed versions: Not specified
node-postcss
Fixed versions: Not specified
node-postcss
Fixed versions: Not specified
node-postcss
Fixed versions: Not specified
node-postcss
Fixed versions: Not specified
node-postcss
Fixed versions: Not specified
Complete source record
{
"id": "8b29185fa70ca550801d4c6bb78becebd01f63384eafe53469614a3da941ea18",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-41305",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-41305",
"summary": "PostCSS takes a CSS file and provides an API to analyze and modify its rules by transforming the rules into an Abstract Syntax Tree. Versions prior to 8.5.10 do not escape `` sequences when stringifying CSS ASTs. When user-submitted CSS is parsed and re-stringified for embedding in HTML `` in CSS values breaks out of the style context, enabling XSS. Version 8.5.10 fixes the issue.",
"evidence": "osv:UBUNTU-CVE-2026-41305",
"products": [
{
"name": {
"value": "node-postcss",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "6.0.23-1",
"evidence": "/affected/0/versions"
},
{
"value": "6.0.23-3",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "node-postcss",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "8.2.1+~cs5.3.23-8",
"evidence": "/affected/1/versions"
},
{
"value": "8.4.5+~cs7.1.51-2",
"evidence": "/affected/1/versions"
},
{
"value": "8.4.6+~cs7.3.21-1",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "node-postcss",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "8.4.20+~cs8.0.23-1",
"evidence": "/affected/2/versions"
},
{
"value": "8.4.31+~cs8.0.26-1",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "node-postcss",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "8.4.49+~cs9.2.32-1",
"evidence": "/affected/3/versions"
},
{
"value": "8.5.6+~cs9.3.28-1",
"evidence": "/affected/3/versions"
}
]
},
{
"name": {
"value": "node-postcss",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "8.5.8+~cs9.3.30-1",
"evidence": "/affected/4/versions"
},
{
"value": "8.5.15+~cs9.3.34-1",
"evidence": "/affected/4/versions"
},
{
"value": "8.5.15+~cs9.3.38-1",
"evidence": "/affected/4/versions"
},
{
"value": "8.5.15+~cs9.3.39-1build1",
"evidence": "/affected/4/versions"
},
{
"value": "8.5.25+~cs10.2.23-1",
"evidence": "/affected/4/versions"
},
{
"value": "8.5.26+~cs10.2.24-1",
"evidence": "/affected/4/versions"
}
]
},
{
"name": {
"value": "node-postcss",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "8.5.6+~cs9.3.28-1",
"evidence": "/affected/5/versions"
},
{
"value": "8.5.8+~cs9.3.30-1",
"evidence": "/affected/5/versions"
}
]
}
],
"severity": "medium",
"structured": {
"id": "UBUNTU-CVE-2026-41305",
"aliases": [
"UBUNTU-CVE-2026-41305"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "node-postcss",
"purl": "pkg:deb/ubuntu/node-postcss?arch=source&distro=focal",
"ecosystem": "Ubuntu:20.04:LTS"
},
"versions": [
"6.0.23-1",
"6.0.23-3"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-41305.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "node-postcss",
"binary_version": "6.0.23-3"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "node-postcss",
"purl": "pkg:deb/ubuntu/node-postcss?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
"8.2.1+~cs5.3.23-8",
"8.4.5+~cs7.1.51-2",
"8.4.6+~cs7.3.21-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-41305.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "node-postcss",
"binary_version": "8.4.6+~cs7.3.21-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "node-postcss",
"purl": "pkg:deb/ubuntu/node-postcss?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"8.4.20+~cs8.0.23-1",
"8.4.31+~cs8.0.26-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-41305.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "node-postcss",
"binary_version": "8.4.31+~cs8.0.26-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "node-postcss",
"purl": "pkg:deb/ubuntu/node-postcss?arch=source&distro=questing",
"ecosystem": "Ubuntu:25.10"
},
"versions": [
"8.4.49+~cs9.2.32-1",
"8.5.6+~cs9.3.28-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-41305.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "node-postcss",
"binary_version": "8.5.6+~cs9.3.28-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "node-postcss",
"purl": "pkg:deb/ubuntu/node-postcss?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
"8.5.8+~cs9.3.30-1",
"8.5.15+~cs9.3.34-1",
"8.5.15+~cs9.3.38-1",
"8.5.15+~cs9.3.39-1build1",
"8.5.25+~cs10.2.23-1",
"8.5.26+~cs10.2.24-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-41305.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "node-postcss",
"binary_version": "8.5.26+~cs10.2.24-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "node-postcss",
"purl": "pkg:deb/ubuntu/node-postcss?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"8.5.6+~cs9.3.28-1",
"8.5.8+~cs9.3.30-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-41305.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "node-postcss",
"binary_version": "8.5.8+~cs9.3.30-1"
}
]
}
}
],
"modified": "2026-10-17T12:58:14.276702748Z",
"provider": "osv",
"upstream": [
"CVE-2026-41305"
],
"references": [
"https://ubuntu.com/security/CVE-2026-41305",
"https://www.cve.org/CVERecord?id=CVE-2026-41305"
]
},
"related_cves": [
{
"value": "CVE-2026-41305",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 358404,
"published_at": "2026-04-24T03:16:00+00:00"
}