Off-by-one in Linux kernel - CVE-2026-72345
Published: August 16, 2026
Vulnerability identifier: #VU143101
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-72345
CWE-ID: CWE-193
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to an off-by-one error in mlx5_lag_create_single_fdb() rollback logic when handling error rollback during single-FDB creation. A local user can trigger a failure during single-FDB creation to cause a denial of service.
The reverse cleanup loop may operate on uninitialized state or double-tear-down a rule that was already rolled back.
Affected software
Linux kernel
Ubuntu
linux-gcp-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
Ubuntu
linux-gcp-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
How to mitigate CVE-2026-72345
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
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-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-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-azure-7.0 (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1017.17~24.04.1