Inefficient regular expression complexity in pymdown-extensions - CVE-2025-68142

 

Inefficient regular expression complexity in pymdown-extensions - CVE-2025-68142

Published: April 28, 2026


Vulnerability identifier: #VU128325
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2025-68142
CWE-ID: CWE-1333
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to inefficient regular expression complexity in pymdownx.blocks.caption when processing unchecked user content. A remote attacker can supply a specially crafted input string to cause a denial of service.

The issue is triggered by a crafted payload that causes excessive processing time during figure caption parsing.


Affected software

pymdown-extensions

How to mitigate CVE-2025-68142

Install security update from vendor's website.

pymdown-extensions - update to 10.16.1

External References

Related Security Bulletins