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CVE-2026-33151
socket.io allows an unbounded number of binary attachments
High8.7EPSS 0.53%
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 4.0 | High8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
| NVDNVD · Analyzed | 4.0 | High8.7 | CVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.53% · top 55% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.7.
Weakness
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- npmsocket.io-parserGHSA-677m-j7p3-52f9 (opens in a new tab)
References (4)
- https://github.com/socketio/socket.io/security/advisories/GHSA-677m-j7p3-52f9 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/socketio/socket.io/commit/719f9ebab0772ffb882bd614b387e585c1aa75d4 (opens in a new tab)x_refsource_MISC
- https://github.com/socketio/socket.io/commit/9d39f1f080510f036782f2177fac701cc041faaf (opens in a new tab)x_refsource_MISC
- https://github.com/socketio/socket.io/commit/b25738c416c4e32fbff62ee182afa8f6d0dacf78 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-677m-j7p3-52f9 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-33151)Record last updated .