CVE-2026-53181
Linux kernel: denial of service
- Risk score
- 48/100
- CVSS
- 5.5 v3.1
- Exploit chance (30 days)
- 0.1%
- Published
- 25 Jun 2026
Open in the live forecast Today's forecast
What to know
- What it is
- 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 increment…
- Affected
- Linux kernel
- Fix
- Apply the vendor's security update; see the linked advisory.
- Exploitation
- No known exploitation
Story map
At a glance
Linux kernel: Amber, patch this week. In the Linux kernel, the following vulnerability has been resolved: ipv6: sr: restore network header before routing and forwarding ipv6_srh_rcv() runs with skb->data at the Segment Routing Header (SRH) while skb_network_header() points at the IPv6 header. When segments_left > 0, ipv6_srh_rcv() previously restored the …
The flaws
- CVE-2026-53181: Denial of service (CVSS 5.5 · EPSS 0%)
- CVE-2026-98096: Out-of-bounds write (CVSS 7.4 · EPSS 1%)
- CVE-2026-98115: Race condition (CVSS 8.8 · EPSS 0%)
- CVE-2026-98117: Use-after-free (CVSS 7.8 · EPSS 0%)
The fix
Fix: Apply the vendor's security update; see the linked advisory.
Who is exposed: Linux kernel
Where it stands
- No known exploitation
How it unfolded
- 6 Nov, Ubuntu security notices (official): USN-9002-1: Linux kernel (NVIDIA Tegra) vulnerabilities
Connects to
- Same weakness: CWE-401 (CWE-401). 45 other warnings in 30 days
- Same product: Earlier Linux kernel warnings. 168 in the last 90 days
Why it is Yellow
- CVSS 5.5 medium
- On your watchlist: linux kernel
- Named in a government or vendor bulletin
Government and vendor bulletins
References
- https://ubuntu.com/security/notices/USN-9002-1
- 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
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html
Original 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.
Last activity 6 Nov 2026. Patch Forecast updates every hour.