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GHSA-gj77-59wh-66hg

HIGH

GHSA-gj77-59wh-66hg is a high-severity (CVSS 7.4) Uncontrolled Resource Consumption vulnerability in prismjs. O3 Security confirms whether GHSA-gj77-59wh-66hg is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Regular Expression Denial of Service (ReDoS) in Prism

Also known asCVE-2021-32723
Published
Jun 28, 2021
Updated
Jul 8, 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.

prismjsnpm
27.2Mdownloads / week

Description

Some languages before 1.24.0 are vulnerable to Regular Expression Denial of Service (ReDoS).

Impact

When Prism is used to highlight untrusted (user-given) text, an attacker can craft a string that will take a very very long time to highlight. Do not use the following languages to highlight untrusted text.

  • ASCIIDoc
  • ERB

Other languages are not affected and can be used to highlight untrusted text.

Patches

This problem has been fixed in Prism v1.24.

References

  • PrismJS/prism#2774
  • PrismJS/prism#2688

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
📦npmprismjsall versions1.24.0

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for prismjs. 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 prismjs to 1.24.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-gj77-59wh-66hg 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-gj77-59wh-66hg 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-gj77-59wh-66hg. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Some languages before 1.24.0 are vulnerable to Regular Expression Denial of Service (ReDoS). ### Impact When Prism is used to highlight untrusted (user-given) text, an attacker can craft a string that will take a very very long time to highlight. Do not use the following languages to highlight untrusted text. - ASCIIDoc - ERB Other languages are __not__ affected and can be used to highlight untrusted text. ### Patches This problem has been fixed in Prism v1.24. ### References - PrismJS/prism#2774 - PrismJS/prism#2688
O3 Security · Impact-Aware SCA

Is GHSA-gj77-59wh-66hg in your dependencies?

O3 detects GHSA-gj77-59wh-66hg across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.