Socket.IO: Zero-attachment Memory Exhaustion
Priority MEDIUM 40CWE-20Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat.
Summary
Socket.IO enables bidirectional and low-latency communication for every platform. Prior to 4.2.7, 3.4.5, and 3.3.6, 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 vulnerability is fixed in 4.2.7, 3.4.5, and 3.3.6.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0063 50th percentileScored 2026-11-07
Fix Partial socket.io (socketio): 3.3.6, 3.4.5, 4.2.7socket.io-parser (npm): 4.2.7, 3.4.5, 3.3.6Red Hat: 1 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| socketio | socket.io | before 3.3.6; 3.4.0 to before 3.4.5; 4.0.0 to before 4.2.7 | 3.3.6, 3.4.5, 4.2.7 | Patch available | CNA |
| — | socket.io-parser (npm) | 4.0.0 to before 4.2.7 | 4.2.7 | Patch available | GHSA-2m8v-j782-fhvr |
| — | socket.io-parser (npm) | 3.4.0 to before 3.4.5 | 3.4.5 | Patch available | GHSA-2m8v-j782-fhvr |
| — | socket.io-parser (npm) | before 3.3.6 | 3.3.6 | Patch available | GHSA-2m8v-j782-fhvr |
- socket.io Vendorsocketio Affected before 3.3.6; 3.4.0 to before 3.4.5; 4.0.0 to before 4.2.7 Fixed in 3.3.6, 3.4.5, 4.2.7 Patch available CNA
- socket.io-parser (npm) Vendor— Affected 4.0.0 to before 4.2.7 Fixed in 4.2.7 Patch available GHSA-2m8v-j782-fhvr
- socket.io-parser (npm) Vendor— Affected 3.4.0 to before 3.4.5 Fixed in 3.4.5 Patch available GHSA-2m8v-j782-fhvr
- socket.io-parser (npm) Vendor— Affected before 3.3.6 Fixed in 3.3.6 Patch available GHSA-2m8v-j782-fhvr
Remediation
- Fix · CNA socket.io (socketio) Fixed in 3.3.6, 3.4.5, 4.2.7
- Fix · GHSA-2m8v-j782-fhvr socket.io-parser (npm) Fixed in 4.2.7 Advisory →
- Fix · GHSA-2m8v-j782-fhvr socket.io-parser (npm) Fixed in 3.4.5 Advisory →
- Fix · GHSA-2m8v-j782-fhvr socket.io-parser (npm) Fixed in 3.3.6 Advisory →
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux AI (RHEL AI) 3 | Affected | No fix yet |
Not affected: 1 product
- Red Hat Hardened Images
Timeline
- 2026-10-02 Threatist record created from CVE-2026-69185
- 2026-10-03 Alias added: GHSA-2m8v-j782-fhvr
- 2026-10-28 EPSS moved to the 50th–90th percentile
References
Other 5
- https://github.com/socketio/socket.io/security/advisories/GHSA-2m8v-j782-fhvr
- https://github.com/socketio/socket.io/commit/7c6ef571a00656718e9e05e3b948fd1758b2a7b4
- https://github.com/socketio/socket.io/commit/9c6323e5cde41bd75df3379b5fc9293664a5f240
- https://github.com/socketio/socket.io/commit/ced94ffa3ac020a8f3c14eb98a3bf34acb14d291
- https://github.com/socketio/socket.io
More socketio vulnerabilities
- TI-2022-20281 Uncaught exception in engine.io CVSS 3.1HIGH 7.1
- TI-2022-02236 Socket.io - Improper type validation in attachment parsing CVSS 3.1CRITICAL 10.0
- TI-2026-25581 socket.io allows an unbounded number of binary attachments CVSS 4.0HIGH 8.7
- TI-2022-06052 Uncaught Exception in engine.io CVSS 3.1HIGH 7.5
- TI-2023-15971 Insufficient validation when decoding a Socket.IO packet CVSS 3.1HIGH 7.5
- TI-2026-73305 Uncaught exception in Engine.IO lets clients crash Node.js processes CVSS 3.1HIGH 7.5
Sources
- CVE-2026-69185 · CVE Program
- CVE-2026-69185 · NVD
- FIRST EPSS
- GHSA-2m8v-j782-fhvr · GitHub Advisory Database · CC BY 4.0
- CVE-2026-69185 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences