MediumFix available
php-league-commonmark — security advisory
league/commonmark is a PHP library for parsing and rendering CommonMark Markdown. From 1.5.0 until 2.9.0, the AttributesExtension's href and src unsafe-link filter can be bypassed by embedding control bytes, such as a tab, carriage return, line feed, or leading C0 control character, in a javascript: URL that browsers discard before parsing the scheme, causing the browser to still execute the script even when the unsafe-link filter is enabled. This issue is fixed in 2.9.0.
- Products
- php-league-commonmark
- Affected versions
- 2.10.0-1, 2.10.1-1, 2.10.3-1, 2.10.4-1, 2.3.9-1, 2.3.9-1+deb12u1, 2.4.0-1, 2.4.1-1, 2.4.2-1, 2.4.2-2, 2.5.0-1, 2.5.1-1, 2.5.3-1, 2.6.0-1, 2.6.1-1, 2.6.1-2, 2.6.2-1, 2.7.0-1, 2.7.0-1+deb13u1, 2.7.1-1, 2.7.1-2, 2.8.0-1, 2.8.1-1, 2.8.2-1, 2.8.2-2, 2.8.3-1, 2.9.0-1
- Fixed versions
- 2.9.0-1
- CVEs
- CVE-2026-71478
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 09:55 UTC · Revision 1
Source evidence
league/commonmark is a PHP library for parsing and rendering CommonMark Markdown. From 1.5.0 until 2.9.0, the AttributesExtension's href and src unsafe-link filter can be bypassed by embedding control bytes, such as a tab, carriage return, line feed, or leading C0 control character, in a javascript: URL that browsers discard before parsing the scheme, causing the browser to still execute the script even when the unsafe-link filter is enabled. This issue is fixed in 2.9.0.
osv:DEBIAN-CVE-2026-71478
php-league-commonmark
Fixed versions: Not specified
php-league-commonmark
Fixed versions: Not specified
php-league-commonmark
Fixed versions: 2.9.0-1
Complete source record
{
"id": "98ae18b8fb14826b37ff16041e4e60c521501c56e27a0024ca885c5b9df3c8df",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-71478",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-71478",
"summary": "league/commonmark is a PHP library for parsing and rendering CommonMark Markdown. From 1.5.0 until 2.9.0, the AttributesExtension's href and src unsafe-link filter can be bypassed by embedding control bytes, such as a tab, carriage return, line feed, or leading C0 control character, in a javascript: URL that browsers discard before parsing the scheme, causing the browser to still execute the script even when the unsafe-link filter is enabled. This issue is fixed in 2.9.0.",
"evidence": "osv:DEBIAN-CVE-2026-71478",
"products": [
{
"name": {
"value": "php-league-commonmark",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.10.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.10.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.10.3-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.10.4-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.3.9-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.3.9-1+deb12u1",
"evidence": "/affected/0/versions"
},
{
"value": "2.4.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.4.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.4.2-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.4.2-2",
"evidence": "/affected/0/versions"
},
{
"value": "2.5.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.5.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.5.3-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.6.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.6.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.6.1-2",
"evidence": "/affected/0/versions"
},
{
"value": "2.6.2-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.7.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.7.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.7.1-2",
"evidence": "/affected/0/versions"
},
{
"value": "2.8.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.8.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.8.2-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.8.2-2",
"evidence": "/affected/0/versions"
},
{
"value": "2.8.3-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.9.0-1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "php-league-commonmark",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.10.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.10.1-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.10.3-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.10.4-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.7.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.7.0-1+deb13u1",
"evidence": "/affected/1/versions"
},
{
"value": "2.7.1-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.7.1-2",
"evidence": "/affected/1/versions"
},
{
"value": "2.8.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.8.1-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.8.2-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.8.2-2",
"evidence": "/affected/1/versions"
},
{
"value": "2.8.3-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.9.0-1",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "php-league-commonmark",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.9.0-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": [
{
"value": "2.7.0-1",
"evidence": "/affected/2/versions"
},
{
"value": "2.7.1-1",
"evidence": "/affected/2/versions"
},
{
"value": "2.7.1-2",
"evidence": "/affected/2/versions"
},
{
"value": "2.8.0-1",
"evidence": "/affected/2/versions"
},
{
"value": "2.8.1-1",
"evidence": "/affected/2/versions"
},
{
"value": "2.8.2-1",
"evidence": "/affected/2/versions"
},
{
"value": "2.8.2-2",
"evidence": "/affected/2/versions"
},
{
"value": "2.8.3-1",
"evidence": "/affected/2/versions"
}
]
}
],
"severity": "medium",
"structured": {
"id": "DEBIAN-CVE-2026-71478",
"aliases": [
"DEBIAN-CVE-2026-71478"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "php-league-commonmark",
"purl": "pkg:deb/debian/php-league-commonmark?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"2.10.0-1",
"2.10.1-1",
"2.10.3-1",
"2.10.4-1",
"2.3.9-1",
"2.3.9-1+deb12u1",
"2.4.0-1",
"2.4.1-1",
"2.4.2-1",
"2.4.2-2",
"2.5.0-1",
"2.5.1-1",
"2.5.3-1",
"2.6.0-1",
"2.6.1-1",
"2.6.1-2",
"2.6.2-1",
"2.7.0-1",
"2.7.1-1",
"2.7.1-2",
"2.8.0-1",
"2.8.1-1",
"2.8.2-1",
"2.8.2-2",
"2.8.3-1",
"2.9.0-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-71478.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "php-league-commonmark",
"purl": "pkg:deb/debian/php-league-commonmark?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"2.10.0-1",
"2.10.1-1",
"2.10.3-1",
"2.10.4-1",
"2.7.0-1",
"2.7.0-1+deb13u1",
"2.7.1-1",
"2.7.1-2",
"2.8.0-1",
"2.8.1-1",
"2.8.2-1",
"2.8.2-2",
"2.8.3-1",
"2.9.0-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-71478.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.9.0-1"
}
]
}
],
"package": {
"name": "php-league-commonmark",
"purl": "pkg:deb/debian/php-league-commonmark?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"2.7.0-1",
"2.7.1-1",
"2.7.1-2",
"2.8.0-1",
"2.8.1-1",
"2.8.2-1",
"2.8.2-2",
"2.8.3-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-71478.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-25T09:47:35.771987994Z",
"provider": "osv",
"upstream": [
"CVE-2026-71478"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-71478"
]
},
"related_cves": [
{
"value": "CVE-2026-71478",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 445297,
"published_at": "2026-08-06T22:18:31.75+00:00"
}