CVE-2026-4923
MEDIUM5.9EPSS 0.02%path-to-regexp vulnerable to Regular Expression Denial of Service via multiple wildcards
Published: 3/27/2026Modified: 4/28/2026
Description
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.
Affected packages (2)
- Debian/node-path-to-regexpfrom 0
- npm/path-to-regexp>= 8.0.0, < 8.4.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
References (6)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-4923
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2026-4923
- PATCHhttps://github.com/pillarjs/path-to-regexp
- WEBhttps://cna.openjsf.org/security-advisories.html
- WEBhttps://github.com/pillarjs/path-to-regexp/security/advisories/GHSA-27v5-c462-wpq7
- WEBhttps://makenowjust-labs.github.io/recheck/playground