CVE-2026-53181
Status: AnalyzedMedium (5.5)—
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.
Read full descriptionShow less
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
- Version: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Base score: 5.5
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days: 0.12%
- Percentile among all scored CVEs: 2
- Score date: 10/4/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
Affected technologies (1)
CWEs
- CWE-401
References
- https://git.kernel.org/stable/c/22c587aa3ab1ab5264daff3ec32136fd30436c13
- https://git.kernel.org/stable/c/9698582a4dd9c4a05889d7db96d4c0edc9e69cac
- https://git.kernel.org/stable/c/ba9ad6015937a5e46ba1a31370e3efdec8abbdcc
- https://git.kernel.org/stable/c/bcb275626055df7f8f947f1a349754b4004d9a15
- https://git.kernel.org/stable/c/c05fa14db43ebef3bd862ca9d073981c0358b3f0
- https://git.kernel.org/stable/c/cf7090e255d74c4b61c51f8ede9fcacdd8393b5b
- https://git.kernel.org/stable/c/dfd853197615d322d3a88dbcab91fc0fd2096219
- https://git.kernel.org/stable/c/ea0b03d52881c12a8c634ea0d6cbfa61cefdb488
Raw JSON (NVD)
Show
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