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GHSA-j3q9-mxjg-w52f

HIGH

GHSA-j3q9-mxjg-w52f is a high-severity (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in path-to-regexp. O3 Security confirms whether GHSA-j3q9-mxjg-w52f is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

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

Also known asCVE-2026-4926
Published
Mar 27, 2026
Updated
Mar 30, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed

Blast Radius

1 pkg affected

Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.

path-to-regexpnpm
211.2Mdownloads / week

Description

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.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
📦npmpath-to-regexp8.0.0&&< 8.4.08.4.0

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for path-to-regexp. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update path-to-regexp to 8.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-j3q9-mxjg-w52f is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether GHSA-j3q9-mxjg-w52f is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-j3q9-mxjg-w52f. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### 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.
O3 Security · Impact-Aware SCA

Is GHSA-j3q9-mxjg-w52f in your dependencies?

O3 detects GHSA-j3q9-mxjg-w52f across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.