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. 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.

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.

How does O3 Security protect against GHSA-mmqv-m45h-q2hp?

O3 pinpoints whether GHSA-mmqv-m45h-q2hp is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

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

GHSA-mmqv-m45h-q2hp

Fix: espadrine/localeval@823f112

GHSA-mmqv-m45h-q2hp is a remote code execution vulnerability in localeval. O3 Security confirms whether GHSA-mmqv-m45h-q2hp is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Sandbox Breakout / Arbitrary Code Execution in localeval

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

📦localeval

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.

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

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for localeval. 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.
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.
How O3 protects you
O3 pinpoints whether GHSA-mmqv-m45h-q2hp 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-mmqv-m45h-q2hp. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

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

Is GHSA-mmqv-m45h-q2hp in your dependencies?

O3 detects GHSA-mmqv-m45h-q2hp across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works