WS-2026-0054
Published:August 03, 2026
Updated:September 02, 2026
league/commonmark's XmlRenderer indented nested elements without any depth limit, so rendering a deeply nested document produced output whose size grew with the nesting depth and can be abused for denial of service. Fixed in 2.9.0 by adding an xml/max_indentation_level option (default 16) that caps how far XmlRenderer indents.
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:
6.9
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
LOW
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Weakness Type (CWE)
Asymmetric Resource Consumption (Amplification)