CVE-2026-53181vsock/vmci: fix sk_ack_backlog leak on failed handshake
- 5.5MediumCVSS base score
- 0.13%Exploitation in 30 daysEPSS · top 98% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: vsock/vmci: fix sk_ack_backlog leak on failed handshake When vmci_transport_recv_connecting_server() returns an error, vmci_transport_recv_listen() calls vsock_remove_pending() but never calls sk_acceptq_removed(). This leaves sk_ack_backlog incremented permanently. Repeated handshake failures (malformed packets, queue pair alloc failure, event subscribe failure) cause sk_ack_backlog to climb toward sk_max_ack_backlog. Once it reaches the limit the listener permanently refuses all new connections with -ECONNREFUSED, a silent denial of service requiring a process restart to recover. The two existing sk_acceptq_removed() calls in af_vsock.c do not cover this path: line 764 checks vsock_is_pending() which returns false after vsock_remove_pending(), and line 1889 is only reached on successful accept(). Fix by balancing sk_acceptq_added() with sk_acceptq_removed() on the error path.
Timeline
ID reserved
By Linux
- 16 days later
· 16 days later
Published
- 4 months later
· 4 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.13% · top 98% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Affected products
- affected d021c344051af91f42c5ba9fdedc176740cbd238 – < 22c587aa3ab1ab5264daff3ec32136fd30436c13
- affected d021c344051af91f42c5ba9fdedc176740cbd238 – < cf7090e255d74c4b61c51f8ede9fcacdd8393b5b
- affected d021c344051af91f42c5ba9fdedc176740cbd238 – < ea0b03d52881c12a8c634ea0d6cbfa61cefdb488
- affected d021c344051af91f42c5ba9fdedc176740cbd238 – < dfd853197615d322d3a88dbcab91fc0fd2096219
- affected d021c344051af91f42c5ba9fdedc176740cbd238 – < bcb275626055df7f8f947f1a349754b4004d9a15
- affected d021c344051af91f42c5ba9fdedc176740cbd238 – < ba9ad6015937a5e46ba1a31370e3efdec8abbdcc
- affected d021c344051af91f42c5ba9fdedc176740cbd238 – < 9698582a4dd9c4a05889d7db96d4c0edc9e69cac
- affected d021c344051af91f42c5ba9fdedc176740cbd238 – < c05fa14db43ebef3bd862ca9d073981c0358b3f0
- affected 3.9
- unaffected < 3.9
- unaffected 5.10.259 – ≤ 5.10.*
- unaffected 5.15.210 – ≤ 5.15.*
- unaffected 6.1.176 – ≤ 6.1.*
- unaffected 6.6.143 – ≤ 6.6.*
- unaffected 6.12.94 – ≤ 6.12.*
- unaffected 6.18.36 – ≤ 6.18.*
- unaffected 7.0.13 – ≤ 7.0.*
- unaffected 7.1 – ≤ *
References
References9
- https://git.kernel.org/stable/c/22c587aa3ab1ab5264daff3ec32136fd30436c13 (opens in a new tab)
- https://git.kernel.org/stable/c/cf7090e255d74c4b61c51f8ede9fcacdd8393b5b (opens in a new tab)
- https://git.kernel.org/stable/c/ea0b03d52881c12a8c634ea0d6cbfa61cefdb488 (opens in a new tab)
- https://git.kernel.org/stable/c/dfd853197615d322d3a88dbcab91fc0fd2096219 (opens in a new tab)
- https://git.kernel.org/stable/c/bcb275626055df7f8f947f1a349754b4004d9a15 (opens in a new tab)
- https://git.kernel.org/stable/c/ba9ad6015937a5e46ba1a31370e3efdec8abbdcc (opens in a new tab)
- https://git.kernel.org/stable/c/9698582a4dd9c4a05889d7db96d4c0edc9e69cac (opens in a new tab)
- https://git.kernel.org/stable/c/c05fa14db43ebef3bd862ca9d073981c0358b3f0 (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)
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)
- EUVD EUVD-2026-39272 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-53181)Record last updated .