SB2026042868 - Inefficient regular expression complexity in pymdown-extensions

Description

This security bulletin contains information about 1 vulnerability.

1) Inefficient regular expression complexity (CVE-ID: CVE-2025-68142)

CWE-ID: CWE-1333 - Inefficient Regular Expression Complexity

CVSSv4: 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

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.

Remediation

Install update from vendor's website.

References

• https://github.com/facelessuser/pymdown-extensions/security/advisories/GHSA-r6h4-mm7h-8pmq
• https://github.com/advisories/GHSA-r6h4-mm7h-8pmq