How severe is GHSA-x4hg-hfwf-p9mw?

No CVSS score has been assigned to GHSA-x4hg-hfwf-p9mw yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-x4hg-hfwf-p9mw?

GHSA-x4hg-hfwf-p9mw affects the following packages: @asymmetric-effort/nogginlessdom (npm). Ecosystems affected: npm.

How do I fix GHSA-x4hg-hfwf-p9mw?

Update @asymmetric-effort/nogginlessdom to 0.0.22 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-x4hg-hfwf-p9mw is resolved across your whole dependency graph.

How do I detect GHSA-x4hg-hfwf-p9mw in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @asymmetric-effort/nogginlessdom, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-x4hg-hfwf-p9mw if there is no patch (or I can't update yet)?

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.

Is GHSA-x4hg-hfwf-p9mw actively exploited in the wild?

No public exploit code has been indexed for GHSA-x4hg-hfwf-p9mw yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was GHSA-x4hg-hfwf-p9mw published, and has it been updated?

GHSA-x4hg-hfwf-p9mw was published on July 2, 2026 and was last updated on September 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

@asymmetric-effort/nogginlessdom vulnerable to ReDoS via user-controlled regex in HTMLInputElement pattern validationGHSA-x4hg-hfwf-p9mw

Fix: asymmetric-effort/NogginLessDom@25a3cba

GHSA-x4hg-hfwf-p9mw is a security vulnerability in @asymmetric-effort/nogginlessdom. A fix is available for @asymmetric-effort/nogginlessdom — see the affected versions and patch details below.

Published

Jul 2, 2026

Updated

Sep 10, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 10, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

0other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

@asymmetric-effort/nogginlessdomnpm

466downloads / week

Description

Summary

The HTMLInputElement.checkValidity() method constructed a RegExp directly from the user-controlled pattern property without any sanitization or timeout protection. This allowed an attacker to inject a regex with catastrophic backtracking, freezing the event loop.

Fix

Fixed in commit https://github.com/asymmetric-effort/NogginLessDom/commit/25a3cbac665fae5663f8b71c073b80c3152dbe7b on main. Added:

Pattern length limit (1024 characters)
Nested quantifier detection (hasNestedQuantifiers) that rejects patterns like (a+)+ before constructing the regex
Patterns exceeding limits are treated as non-matching (safe default)

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@asymmetric-effort/nogginlessdom`	all versions	0.0.22`npm install @asymmetric-effort/nogginlessdom@0.0.22`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @asymmetric-effort/nogginlessdom, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @asymmetric-effort/nogginlessdom to 0.0.22 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-x4hg-hfwf-p9mw is resolved across your whole dependency graph.
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.

Frequently Asked Questions

## Summary The `HTMLInputElement.checkValidity()` method constructed a `RegExp` directly from the user-controlled `pattern` property without any sanitization or timeout protection. This allowed an attacker to inject a regex with catastrophic backtracking, freezing the event loop. ## Fix Fixed in commit https://github.com/asymmetric-effort/NogginLessDom/commit/25a3cbac665fae5663f8b71c073b80c3152dbe7b on `main`. Added: - Pattern length limit (1024 characters) - Nested quantifier detection (`hasNestedQuantifiers`) that rejects patterns like `(a+)+` before constructing the regex - Patterns exce

O3 Security · Impact-Aware SCA

Is GHSA-x4hg-hfwf-p9mw in your dependencies?

Find it across npm, including transitive dependencies.

Scan my dependencies How O3 SCA works