Description (CNA)
league/commonmark versions >= 2.0.0 and < 2.8.4 (patched in 2.9.0) contain a denial of service vulnerability in UniqueSlugNormalizer::normalize(), which restarts its numeric-suffix search from 1 on every slug collision, resulting in O(K^2) time complexity for K headings that collapse to the same base slug. The vulnerable path is reached when HeadingPermalinkExtension, FootnoteExtension, or TableOfContentsExtension is registered. An unauthenticated attacker can force many headings onto a single base slug (e.g., via empty ATX headings, identical heading text, or punctuation-only headings) in a small Markdown document, consuming excessive CPU and denying service.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| thephpleague / commonmark | affected 2.0.0 before 2.8.4; unaffected 2.8.4 |
CWE
CWE-407
References
- https://github.com/thephpleague/commonmark/security/advisories/GHSA-mh25-x5hq-wrqp
- https://www.vulncheck.com/advisories/commonmark-2.0.0-through-2.8.3-denial-of-service-via-slug-collision
ADP enrichment
No English description supplied.
No references supplied.