CVE-2026-4923

Impact: When using multiple wildcards, combined with at least one parameter, a regular expression can be generated that is vulnerable to ReDoS. This backtracking vulnerability requires the second wildcard to be somewhere other than the end of the path. Unsafe examples: /*foo-*bar-:baz /*a-:b-*c-:d /x/*a-:b/*c/y Safe examples: /*foo-:bar /*foo-:bar-*baz Patches: Upgrade to version 8.4.0. Workarounds: If you are using multiple wildcard parameters, you can check the regex output with a tool such as https://makenowjust-labs.github.io/recheck/playground/ to confirm whether a path is vulnerable.

Score

CVSS 3.1 5.9 Medium

Status

Analyzed - ce714d77-add3-4f53-aff5-83d477b104bb

Published

2026-03-26

Last modified

2026-03-27

Weaknesses

CWE-1333

Affected products

• Path-to-regexp (Path-to-regexp)
• Path-to-regexp (Pillarjs)

References

• https://cna.openjsf.org/security-advisories.html