HIGH7.5

GHSA-j3q9-mxjg-w52f

path-to-regexp vulnerable to Denial of Service via sequential optional groups

Quick fix

GHSA-j3q9-mxjg-w52f — path-to-regexp: upgrade to the fixed version with the command below.

npm install path-to-regexp@8.4.0

Details

### Impact

A bad regular expression is generated any time you have multiple sequential optional groups (curly brace syntax), such as `{a}{b}{c}:z`. The generated regex grows exponentially with the number of groups, causing denial of service.

### Patches

Fixed in version 8.4.0.

### Workarounds

Limit the number of sequential optional groups in route patterns. Avoid passing user-controlled input as route patterns.

Are you affected?

Enter the version of the package you're using.

Affected packages

npm/path-to-regexp

Introduced in: 8.0.0Fixed in: 8.4.0

Fixnpm install path-to-regexp@8.4.0

References

https://github.com/pillarjs/path-to-regexp/security/advisories/GHSA-j3q9-mxjg-w52f[WEB]
https://nvd.nist.gov/vuln/detail/CVE-2026-4926[ADVISORY]
https://cna.openjsf.org/security-advisories.html[WEB]
https://github.com/pillarjs/path-to-regexp[PACKAGE]