Use-after-free in Linux kernel - CVE-2026-68140
Published: August 12, 2026
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to use-after-free in the af_iucv message queue handling when processing queued message notifications after a connection is severed. A local user can trigger connection severing with queued notifications still pending and then invoke recvmsg() to cause a denial of service.
The issue occurs because queued notifications retain stale references to a freed iucv_path.
Affected software
Ubuntu
linux-nvidia (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-azure (Ubuntu package)
How to mitigate CVE-2026-68140
linux-nvidia (Ubuntu package) - addressed in versions 5.15.0-1112.113, 5.15.0.1112.112
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1036.39+1
linux-gcp-7.0 (Ubuntu package) - addressed in versions 7.0.0-38.38~24.04.4, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14~24.04.1
linux (Ubuntu package) - addressed in versions 7.0.0-38.38, 7.0.0-38.38.1, 7.0.0-1008.9, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1015.15
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1015.15
linux-azure-7.0 (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1017.17~24.04.1
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1017.17
External References
- https://git.kernel.org/stable/c/23658b350b4107e8292045c2044983fd426fa15d
- https://git.kernel.org/stable/c/900cd6d8119b7f3ae5c4bf82f922ff5957df43db
- https://git.kernel.org/stable/c/a5bbaddf69853117f28173c3f5c8fc14c6b2ec82
- https://git.kernel.org/stable/c/be7cc4656eb1f54029610e82d1f0fdd3f9b5ec0a
- https://git.kernel.org/stable/c/f579582c03ed526281a8450159baf1d35099a85f