CVE-2026-53181vsock/vmci: fix sk_ack_backlog leak on failed handshake
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Modified
- Record last updated
- Oct 15, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from d021c344051af91f42c5ba9fdedc176740cbd238 before 22c587aa3ab1ab5264daff3ec32136fd30436c13; from d021c344051af91f42c5ba9fdedc176740cbd238 before cf7090e255d74c4b61c51f8ede9fcacdd8393b5b; from d021c344051af91f42c5ba9fdedc176740cbd238 before ea0b03d52881c12a8c634ea0d6cbfa61cefdb488; from d021c344051af91f42c5ba9fdedc176740cbd238 before dfd853197615d322d3a88dbcab91fc0fd2096219; from d021c344051af91f42c5ba9fdedc176740cbd238 before bcb275626055df7f8f947f1a349754b4004d9a15; from d021c344051af91f42c5ba9fdedc176740cbd238 before ba9ad6015937a5e46ba1a31370e3efdec8abbdcc; from d021c344051af91f42c5ba9fdedc176740cbd238 before 9698582a4dd9c4a05889d7db96d4c0edc9e69cac; from d021c344051af91f42c5ba9fdedc176740cbd238 before c05fa14db43ebef3bd862ca9d073981c0358b3f0 | CNA record |
Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem siemens:simatic_s7_1500_tm_mfp_gnu_linux_subsystem (from the name) | all versions | CISA ADP |
linux linux_kernel linux:linux_kernel | from 3.9 before 5.10.259; from 5.11 before 5.15.210; from 5.16 before 6.1.176; from 6.2 before 6.6.143; from 6.7 before 6.12.94; from 6.13 before 6.18.36; from 6.19 before 7.0.13; 7.1; and 5 more ranges | NVD |
References
- https://git.kernel.org/stable/c/22c587aa3ab1ab5264daff3ec32136fd30436c13patch
- https://git.kernel.org/stable/c/cf7090e255d74c4b61c51f8ede9fcacdd8393b5bpatch
- https://git.kernel.org/stable/c/ea0b03d52881c12a8c634ea0d6cbfa61cefdb488patch
- https://git.kernel.org/stable/c/dfd853197615d322d3a88dbcab91fc0fd2096219patch
- https://git.kernel.org/stable/c/bcb275626055df7f8f947f1a349754b4004d9a15patch
- https://git.kernel.org/stable/c/ba9ad6015937a5e46ba1a31370e3efdec8abbdccpatch
- https://git.kernel.org/stable/c/9698582a4dd9c4a05889d7db96d4c0edc9e69cacpatch
- https://git.kernel.org/stable/c/c05fa14db43ebef3bd862ca9d073981c0358b3f0patch
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.