Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
📦
📦 npm
Not in CISA KEV
HIGH severity

GHSA-6chw-6frg-f759

HIGHFix: acornjs/acorn@793c0e5

GHSA-6chw-6frg-f759 is a high-severity (CVSS 7.5) vulnerability in acorn. O3 Security confirms whether GHSA-6chw-6frg-f759 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Regular Expression Denial of Service in Acorn

Published
Apr 3, 2020
Updated
Aug 23, 2021
Affected
3 pkgs
Patched
3 / 3
Exploits
None indexed
Exploitation data as of Aug 23, 2021 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

3 pkgs 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.

10Kother npm packages depend on this — each one inherits the vulnerability until it's patched upstream
acornnpm
253.8Mdownloads / week

Description

Affected versions of acorn are vulnerable to Regular Expression Denial of Service. A regex in the form of /[x-\ud800]/u causes the parser to enter an infinite loop. The string is not valid UTF16 which usually results in it being sanitized before reaching the parser. If an application processes untrusted input and passes it directly to acorn, attackers may leverage the vulnerability leading to Denial of Service.

Affected Packages

3 total 3 fixed
EcosystemPackageVulnerable rangeFix
📦npmacorn5.5.0&&< 5.7.45.7.4
📦npmacorn6.0.0&&< 6.4.16.4.1
📦npmacorn7.0.0&&< 7.1.17.1.1

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for acorn. 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 acorn to 5.7.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6chw-6frg-f759 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-6chw-6frg-f759 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-6chw-6frg-f759. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Affected versions of acorn are vulnerable to Regular Expression Denial of Service. A regex in the form of /[x-\ud800]/u causes the parser to enter an infinite loop. The string is not valid UTF16 which usually results in it being sanitized before reaching the parser. If an application processes untrusted input and passes it directly to acorn, attackers may leverage the vulnerability leading to Denial of Service.
O3 Security · Impact-Aware SCA

Is GHSA-6chw-6frg-f759 in your dependencies?

O3 detects GHSA-6chw-6frg-f759 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

GHSA-6chw-6frg-f759: Regular Expression… | O3 Security