How severe is CVE-2024-38355?

CVE-2024-38355 has a CVSS score of 7.3/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2024-38355?

CVE-2024-38355 affects the following packages: socket.io (npm), socket.io (npm). Ecosystems affected: npm.

How do I fix CVE-2024-38355?

Update socket.io to 2.5.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-38355 is resolved across your whole dependency graph.

How do I detect CVE-2024-38355 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for socket.io. 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-2024-38355 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-2024-38355?

O3 pinpoints whether CVE-2024-38355 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-2024-38355 actively exploited in the wild?

No public exploit code has been indexed for CVE-2024-38355 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-2024-38355?

CVE-2024-38355 has an EPSS (Exploit Prediction Scoring System) score of 0.7%, placing it in the 48th 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.

When was CVE-2024-38355 published, and has it been updated?

CVE-2024-38355 was published on June 19, 2024 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.

📦 npm

CVE-2024-38355

HIGH

Unhandled 'error' event in socket.io

Also known asGHSA-25hc-qcg6-38wj

Published

Jun 19, 2024

Updated

Apr 10, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.7%probability of exploitation in next 30 days

Lower Risk48th percentile+0.55%

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

2 pkgs affected

📦socket.io📦socket.io

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

Socket.IO is an open source, real-time, bidirectional, event-based, communication framework. A specially crafted Socket.IO packet can trigger an uncaught exception on the Socket.IO server, thus killing the Node.js process. This issue is fixed by commit 15af22fc22 which has been included in [email protected] (released in May 2023). The fix was backported in the 2.x branch as well with commit d30630ba10. Users are advised to upgrade. Users unable to upgrade may attach a listener for the "error" event to catch these errors.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`socket.io`	all versions	2.5.1
📦npm	`socket.io`	≥ 3.0.0&&< 4.6.2	4.6.2

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for socket.io. 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 socket.io to 2.5.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-38355 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-2024-38355 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-2024-38355. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Socket.IO is an open source, real-time, bidirectional, event-based, communication framework. A specially crafted Socket.IO packet can trigger an uncaught exception on the Socket.IO server, thus killing the Node.js process. This issue is fixed by commit `15af22fc22` which has been included in `[email protected]` (released in May 2023). The fix was backported in the 2.x branch as well with commit `d30630ba10`. Users are advised to upgrade. Users unable to upgrade may attach a listener for the "error" event to catch these errors.

O3 Security · Impact-Aware SCA

Is CVE-2024-38355 in your dependencies?

O3 detects CVE-2024-38355 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