How severe is GHSA-f52g-6jhx-586p?

No CVSS score has been assigned to GHSA-f52g-6jhx-586p yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-f52g-6jhx-586p?

GHSA-f52g-6jhx-586p affects the following packages: handlebars (npm). Ecosystems affected: npm.

How do I fix GHSA-f52g-6jhx-586p?

Update handlebars to 4.4.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-f52g-6jhx-586p is resolved across your whole dependency graph.

How do I detect GHSA-f52g-6jhx-586p in my npm dependencies?

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

How do I mitigate GHSA-f52g-6jhx-586p if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is GHSA-f52g-6jhx-586p actively exploited in the wild?

No public exploit code has been indexed for GHSA-f52g-6jhx-586p 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-f52g-6jhx-586p published, and has it been updated?

GHSA-f52g-6jhx-586p was published on September 3, 2020 and was last updated on August 31, 2020. 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

Denial of Service in handlebarsGHSA-f52g-6jhx-586p

GHSA-f52g-6jhx-586p is a security vulnerability in handlebars. A fix is available for handlebars — see the affected versions and patch details below.

Published

Sep 3, 2020

Updated

Aug 31, 2020

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Aug 31, 2020 · 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.

17Kother npm packages depend on this — each one inherits the vulnerability until it's patched upstream

handlebarsnpm

41.5Mdownloads / week

Description

Affected versions of handlebars are vulnerable to Denial of Service. The package's parser may be forced into an endless loop while processing specially-crafted templates. This may allow attackers to exhaust system resources leading to Denial of Service.

Recommendation

Upgrade to version 4.4.5 or later.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`handlebars`	≥ 4.0.0&&< 4.4.5	4.4.5`npm install handlebars@4.4.5`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for handlebars, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update handlebars to 4.4.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-f52g-6jhx-586p is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

Affected versions of `handlebars` are vulnerable to Denial of Service. The package's parser may be forced into an endless loop while processing specially-crafted templates. This may allow attackers to exhaust system resources leading to Denial of Service. ## Recommendation Upgrade to version 4.4.5 or later.

O3 Security · Impact-Aware SCA

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