{"id":"CVE-2026-53181","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nvsock/vmci: fix sk_ack_backlog leak on failed handshake\n\nWhen vmci_transport_recv_connecting_server() returns an error,\nvmci_transport_recv_listen() calls vsock_remove_…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nvsock/vmci: fix sk_ack_backlog leak on failed handshake\n\nWhen vmci_transport_recv_connecting_server() returns an error,\nvmci_transport_recv_listen() calls vsock_remove_…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-401"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 3.9, < 5.10.259","linux_kernel >= 5.11, < 5.15.210","linux_kernel >= 5.16, < 6.1.176","linux_kernel >= 6.2, < 6.6.143","linux_kernel >= 6.7, < 6.12.94","linux_kernel >= 6.13, < 6.18.36","linux_kernel >= 6.19, < 7.0.13","linux_kernel = 7.1"],"patched":["linux_kernel 7.0.13"],"published":"2026-06-25","updated":"2026-10-15","sourceUpdated":"2026-10-15T02:20:03.340","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-53181","references":[{"url":"https://git.kernel.org/stable/c/22c587aa3ab1ab5264daff3ec32136fd30436c13","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9698582a4dd9c4a05889d7db96d4c0edc9e69cac","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ba9ad6015937a5e46ba1a31370e3efdec8abbdcc","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bcb275626055df7f8f947f1a349754b4004d9a15","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c05fa14db43ebef3bd862ca9d073981c0358b3f0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cf7090e255d74c4b61c51f8ede9fcacdd8393b5b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/dfd853197615d322d3a88dbcab91fc0fd2096219","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ea0b03d52881c12a8c634ea0d6cbfa61cefdb488","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-784472.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00123,"epssPercentile":0.01833,"ingestedAt":"2026-10-15T03:30:12.907Z","slug":"CVE-2026-53181","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nvsock/vmci: fix sk_ack_backlog leak on failed handshake\n\nWhen vmci_transport_recv_connecting_server() returns an error,\nvmci_transport_recv_listen() calls vsock_remove_pending() but never\ncalls sk_acceptq_removed(). This leaves sk_ack_backlog incremented\npermanently.\n\nRepeated handshake failures (malformed packets, queue pair alloc\nfailure, event subscribe failure) cause sk_ack_backlog to climb\ntoward sk_max_ack_backlog. Once it reaches the limit the listener\npermanently refuses all new connections with -ECONNREFUSED, a\nsilent denial of service requiring a process restart to recover.\n\nThe two existing sk_acceptq_removed() calls in af_vsock.c do not\ncover this path: line 764 checks vsock_is_pending() which returns\nfalse after vsock_remove_pending(), and line 1889 is only reached\non successful accept().\n\nFix by balancing sk_acceptq_added() with sk_acceptq_removed() on\nthe error path.\n\n## Affected\n\n- `linux_kernel >= 3.9, < 5.10.259`\n- `linux_kernel >= 5.11, < 5.15.210`\n- `linux_kernel >= 5.16, < 6.1.176`\n- `linux_kernel >= 6.2, < 6.6.143`\n- `linux_kernel >= 6.7, < 6.12.94`\n- `linux_kernel >= 6.13, < 6.18.36`\n- `linux_kernel >= 6.19, < 7.0.13`\n- `linux_kernel = 7.1`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 7.0.13`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}