Analysis
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Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| thephpleague | commonmark | unaffected |
|
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No data available yet.
No vendor fix or workaround currently provided.
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Tracking
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Mon, 07 Sep 2026 13:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | commonmark 2.0.0 through 2.8.3 Denial of Service via Slug Collision | |
| First Time appeared |
Thephpleague
Thephpleague commonmark |
|
| Weaknesses | CWE-407 | |
| CPEs | cpe:2.3:a:thephpleague:commonmark:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Thephpleague
Thephpleague commonmark |
|
| References |
| |
| Metrics |
cvssV3_1
|
MITRE
Status: PUBLISHED
Assigner: VulnCheck
Published:
Updated: 2026-09-07T12:53:53.194Z
Reserved: 2026-09-07T12:34:31.457Z
Link: CVE-2026-86434
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-07T13:20:42.870
Modified: 2026-09-07T13:20:42.870
Link: CVE-2026-86434
Redhat
No data.
OpenCVE Enrichment
No data.