commonmark 1.5.0 before 2.8.4 Denial of Service via Attributes
commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Attributes extension where AttributesListener::findTargetAndDirection() performs quadratic-time sibling list scanning. Unauthenticated attackers can submit approximately 32 KB of repeated attribute blocks to cause parsing to take over 5 seconds, exhausting server resources.
CVE-2026-86433
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-86433
commonmark
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "thephpleague",
"product": "commonmark",
"versions": [
{
"status": "affected",
"version": "1.5.0",
"lessThan": "2.8.4",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "2.8.4",
"versionType": "semver"
}
],
"packageURL": "pkg:composer/league/commonmark",
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-86433
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #12949 · Revision 1
- Added to Heist Feed
- Publisher date