Inefficient regular expression complexity in pymdown-extensions - CVE-2025-68142
Published: April 28, 2026
Vulnerability identifier: #VU128325
CSH Severity: Medium
CVSS v4.0: 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/E:U/U:Green
CVE-ID: CVE-2025-68142
CWE-ID: CWE-1333
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: facelessuser (Isaac Muse)
Affected software:
pymdown-extensions
pymdown-extensions
Detailed vulnerability description
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.
How to mitigate CVE-2025-68142
Install security update from vendor's website.