Engine.IO is the implementation of transport-based cross-browser/cross-device bi-directional communication layer for Socket.IO. An uncaught exception vulnerability was introduced in version 5.1.0 and included in version 4.1.0 of the socket.io parent package. Older versions are not impacted. A specially crafted HTTP request can trigger an uncaught exception on the Engine.IO server, thus killing the Node.js process. This impacts all the users of the engine.io package, including those who use depending packages like socket.io. This issue was fixed in version 6.4.2 of Engine.IO. There is no known workaround except upgrading to a safe version.
CVE-2023-31125
This medium-severity CVE scores 6.5 under NVD CVSS v3. EPSS exploit probability: 0.9%, top 24% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.5
- EG Score
- 6.5(medium)
- EPSS
- 68.0%
- KEV
- Not listed
Published
May 8, 2023
Last Modified
February 13, 2025
References (8)
- security-advisories@githubhttps://github.com/socketio/engine.io/commit/fc480b4f305e16fe5972cf337d055e598372dc44
- security-advisories@githubhttps://github.com/socketio/engine.io/releases/tag/6.4.2
- security-advisories@githubhttps://github.com/socketio/engine.io/security/advisories/GHSA-q9mw-68c2-j6m5
- security-advisories@githubhttps://security.netapp.com/advisory/ntap-20230622-0002/
- af854a3a-2127-422b-91ae-364da2661108https://github.com/socketio/engine.io/commit/fc480b4f305e16fe5972cf337d055e598372dc44
- af854a3a-2127-422b-91ae-364da2661108https://github.com/socketio/engine.io/releases/tag/6.4.2
- af854a3a-2127-422b-91ae-364da2661108https://github.com/socketio/engine.io/security/advisories/GHSA-q9mw-68c2-j6m5
- af854a3a-2127-422b-91ae-364da2661108https://security.netapp.com/advisory/ntap-20230622-0002/
Affected Packages
(1 across 1 ecosystem)
npm(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| engine.io | — | 6.4.2 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 12× in last 7d / 46× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
Showing the most recent 100 of 102 total refreshes for this CVE.
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Frequently asked(5)
What is CVE-2023-31125?
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Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2023-31125
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