How severe is CVE-2025-61927?

No CVSS score has been assigned to CVE-2025-61927 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2025-61927?

CVE-2025-61927 affects the following packages: happy-dom (npm). Ecosystems affected: npm.

How do I fix CVE-2025-61927?

Update happy-dom to 20.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-61927 is resolved across your whole dependency graph.

How do I detect CVE-2025-61927 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for happy-dom. 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 CVE-2025-61927 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 CVE-2025-61927?

O3 pinpoints whether CVE-2025-61927 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 CVE-2025-61927 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-61927 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.

What is the EPSS score for CVE-2025-61927?

CVE-2025-61927 has an EPSS (Exploit Prediction Scoring System) score of 0.6%, placing it in the 44th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2025-61927?

CVE-2025-61927 is classified as Code Injection (CWE-94). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2025-61927 published, and has it been updated?

CVE-2025-61927 was published on October 10, 2025 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2025-61927: Happy-DOM has VM Context Escape

EPSS Exploitation Probability

via FIRST.org ↗

0.6%probability of exploitation in next 30 days

Lower Risk44th percentile+0.02%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

📦happy-dom

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

Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. Happy DOM v19 and lower contains a security vulnerability that puts the owner system at the risk of RCE (Remote Code Execution) attacks. A Node.js VM Context is not an isolated environment, and if the user runs untrusted JavaScript code within the Happy DOM VM Context, it may escape the VM and get access to process level functionality. It seems like what the attacker can get control over depends on if the process is using ESM or CommonJS. With CommonJS the attacker can get hold of the require() function to import modules. Happy DOM has JavaScript evaluation enabled by default. This may not be obvious to the consumer of Happy DOM and can potentially put the user at risk if untrusted code is executed within the environment. Version 20.0.0 patches the issue by changing JavaScript evaluation to be disabled by default.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`happy-dom`	all versions	20.0.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for happy-dom. 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 happy-dom to 20.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-61927 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 CVE-2025-61927 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 CVE-2025-61927. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. Happy DOM v19 and lower contains a security vulnerability that puts the owner system at the risk of RCE (Remote Code Execution) attacks. A Node.js VM Context is not an isolated environment, and if the user runs untrusted JavaScript code within the Happy DOM VM Context, it may escape the VM and get access to process level functionality. It seems like what the attacker can get control over depends on if the process is using ESM or CommonJS. With CommonJS the attacker can get hold of the `require()` fu

O3 Security · Impact-Aware SCA

Is CVE-2025-61927 in your dependencies?

O3 detects CVE-2025-61927 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

CVE-2025-61927