HighFix available
php-league-commonmark — security advisory
league/commonmark versions before 2.9.1 contain multiple denial of service vulnerabilities in fenced code block detection, reference link label lookup, and emphasis delimiter processing that perform super-linear work on crafted input. Attackers can submit specially crafted Markdown with long backtick runs, nested brackets, or delimiter sequences to consume disproportionate CPU time and prevent legitimate requests from completing.
- Products
- php-league-commonmark
- Affected versions
- 2.10.0-1, 2.10.1-1, 2.10.3-1, 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
- 2.10.0-1
- CVEs
- CVE-2026-86430
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 28 Oct 2026, 11:09 UTC · Revision 1
Source evidence
league/commonmark versions before 2.9.1 contain multiple denial of service vulnerabilities in fenced code block detection, reference link label lookup, and emphasis delimiter processing that perform super-linear work on crafted input. Attackers can submit specially crafted Markdown with long backtick runs, nested brackets, or delimiter sequences to consume disproportionate CPU time and prevent legitimate requests from completing.
osv:DEBIAN-CVE-2026-86430
php-league-commonmark
Fixed versions: Not specified
php-league-commonmark
Fixed versions: Not specified
php-league-commonmark
Fixed versions: 2.10.0-1
Complete source record
{
"id": "cb998e3a00e3afd23536414957fab57d60991e62fe04dd825887606fb0986273",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-86430",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-86430",
"summary": "league/commonmark versions before 2.9.1 contain multiple denial of service vulnerabilities in fenced code block detection, reference link label lookup, and emphasis delimiter processing that perform super-linear work on crafted input. Attackers can submit specially crafted Markdown with long backtick runs, nested brackets, or delimiter sequences to consume disproportionate CPU time and prevent legitimate requests from completing.",
"evidence": "osv:DEBIAN-CVE-2026-86430",
"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": "2.3.9-1",
"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": "2.7.0-1",
"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": "2.10.0-1",
"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"
},
{
"value": "2.9.0-1",
"evidence": "/affected/2/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2026-86430",
"aliases": [
"DEBIAN-CVE-2026-86430"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
}
],
"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",
"2.3.9-1",
"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-2026-86430.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",
"2.7.0-1",
"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-2026-86430.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.10.0-1"
}
]
}
],
"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",
"2.9.0-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-86430.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-09T09:47:36.783906854Z",
"provider": "osv",
"upstream": [
"CVE-2026-86430"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-86430"
]
},
"related_cves": [
{
"value": "CVE-2026-86430",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 111718,
"published_at": "2026-09-07T13:20:42.32+00:00"
}