HighFix available
php-league-commonmark — security advisory
commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Footnote extension that fails to deduplicate footnote definitions. Attackers can craft documents with duplicate footnote definitions and references to create quadratic output expansion, consuming excessive memory and CPU to exhaust server resources.
- 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
- 2.9.0-1
- CVEs
- CVE-2026-86435
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 28 Oct 2026, 11:08 UTC · Revision 1
Source evidence
commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Footnote extension that fails to deduplicate footnote definitions. Attackers can craft documents with duplicate footnote definitions and references to create quadratic output expansion, consuming excessive memory and CPU to exhaust server resources.
osv:DEBIAN-CVE-2026-86435
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": "fc3b082b8f1fa6f39bdc3b7dff8328ba4da82170c3fdcf17041c46a5ca016ed0",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-86435",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-86435",
"summary": "commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Footnote extension that fails to deduplicate footnote definitions. Attackers can craft documents with duplicate footnote definitions and references to create quadratic output expansion, consuming excessive memory and CPU to exhaust server resources.",
"evidence": "osv:DEBIAN-CVE-2026-86435",
"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": "2.9.0-1",
"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": "high",
"structured": {
"id": "DEBIAN-CVE-2026-86435",
"aliases": [
"DEBIAN-CVE-2026-86435"
],
"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-2026-86435.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-2026-86435.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-2026-86435.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-09T09:47:33.520427560Z",
"provider": "osv",
"upstream": [
"CVE-2026-86435"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-86435"
]
},
"related_cves": [
{
"value": "CVE-2026-86435",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 111652,
"published_at": "2026-09-07T13:20:43.013+00:00"
}