How severe is GHSA-mmqv-m45h-q2hp?

No CVSS score has been assigned to GHSA-mmqv-m45h-q2hp yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-mmqv-m45h-q2hp?

GHSA-mmqv-m45h-q2hp affects the following packages: localeval (npm). Ecosystems affected: npm.

How do I fix GHSA-mmqv-m45h-q2hp?

Update localeval to 15.3.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mmqv-m45h-q2hp is resolved across your whole dependency graph.

How do I detect GHSA-mmqv-m45h-q2hp in my npm dependencies?

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

How do I mitigate GHSA-mmqv-m45h-q2hp 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-mmqv-m45h-q2hp actively exploited in the wild?

No public exploit code has been indexed for GHSA-mmqv-m45h-q2hp 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-mmqv-m45h-q2hp published, and has it been updated?

GHSA-mmqv-m45h-q2hp was published on September 4, 2020 and was last updated on February 3, 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

Sandbox Breakout / Arbitrary Code Execution in localevalGHSA-mmqv-m45h-q2hp

Fix: espadrine/localeval@823f112

GHSA-mmqv-m45h-q2hp is a remote code execution vulnerability in localeval. A fix is available for localeval — see the affected versions and patch details below.

Published

Sep 4, 2020

Updated

Feb 3, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Feb 3, 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.

9other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

localevalnpm

98downloads / week

Description

All versions of localeval are vulnerable to Sandbox Escape leading to Remote Code Execution. The package fails to restrict access to the main context through constructor.constructor. This may allow attackers to execute arbitrary code in the system. Evaluating the payload

constructor.constructor("return process.env")()

returns the contents of process.env.

Recommendation

No fix is currently available. Consider using an alternative package until a fix is made available.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`localeval`	all versions	15.3.0`npm install localeval@15.3.0`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for localeval, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update localeval to 15.3.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mmqv-m45h-q2hp 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

All versions of `localeval` are vulnerable to Sandbox Escape leading to Remote Code Execution. The package fails to restrict access to the main context through `constructor.constructor`. This may allow attackers to execute arbitrary code in the system. Evaluating the payload ``` constructor.constructor("return process.env")() ``` returns the contents of `process.env`. ## Recommendation No fix is currently available. Consider using an alternative package until a fix is made available.

O3 Security · Impact-Aware SCA

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