VulnerabilityAnalyzed
CVE-2026-33151
Socket.IO is an open source, real-time, bidirectional, event-based, communication framework.
HIGH 8.7EPSS 0.51%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.51%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Socket.IO is an open source, real-time, bidirectional, event-based, communication framework. Prior to versions 3.3.5, 3.4.4, and 4.2.6, a specially crafted Socket.IO packet can make the server wait for a large number of binary attachments and buffer them, which can be exploited to make the server run out of memory. This issue has been patched in versions 3.3.5, 3.4.4, and 4.2.6.
- CVSS 4.0
- 8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.51% probability · 42th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-20, CWE-754
- Affected
- socket/socket.io-parser
- Source
- security-advisories@github.com
References
- https://github.com/socketio/socket.io/commit/719f9ebab0772ffb882bd614b387e585c1aa75d4Patch
- https://github.com/socketio/socket.io/commit/9d39f1f080510f036782f2177fac701cc041faafPatch
- https://github.com/socketio/socket.io/commit/b25738c416c4e32fbff62ee182afa8f6d0dacf78Patch
- https://github.com/socketio/socket.io/security/advisories/GHSA-677m-j7p3-52f9Patch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.