WS-2026-0059
Published:August 03, 2026
Updated:September 02, 2026
league/commonmark de-duplicated slugs in quadratic time, so a document whose headings and inline footnotes repeatedly normalize to the same slug can be abused for denial of service. Fixed in 2.9.0 by tracking slug collisions with a counter instead of re-scanning the accumulated history for each new slug.
Affected Packages
https://github.com/thephpleague/commonmark.git (GITHUB):
Affected version(s) >=2.0.0 <2.9.0Fix Suggestion:
Update to version 2.9.0league/commonmark (PHP):
Affected version(s) >=2.0.0 <2.9.0Fix Suggestion:
Update to version 2.9.0Related Resources (2)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Inefficient Algorithmic Complexity