Vulnerability · Published Mar 26, 2026 · Assigned by openjs
CVE-2026-4923path-to-regexp vulnerable to Regular Expression Denial of Service via multiple wildcards
Medium 5.9
In plain English
A medium-severity regular-expression denial of service in path-to-regexp from path-to-regexp. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 30% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | node-path-to-regexp | no fix listed | DEBIAN-CVE-2026-4923 |
| Debian:13 | node-path-to-regexp | no fix listed | DEBIAN-CVE-2026-4923 |
| Debian:14 | node-path-to-regexp | 8.4.0-1 | DEBIAN-CVE-2026-4923 |
| Ubuntu:22.04:LTS | node-path-to-regexp | no fix listed | UBUNTU-CVE-2026-4923 |
| Ubuntu:24.04:LTS | node-path-to-regexp | no fix listed | UBUNTU-CVE-2026-4923 |
| Ubuntu:25.10 | node-path-to-regexp | no fix listed | UBUNTU-CVE-2026-4923 |
| Ubuntu:26.04:LTS | node-path-to-regexp | no fix listed | UBUNTU-CVE-2026-4923 |
| npm | path-to-regexp | 8.4.0 | GHSA-27v5-c462-wpq7 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| path-to-regexp | path-to-regexp | 8.0.0 – before 8.4.0 |
Weakness: CWE-1333 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H