Integer underflow in Linux kernel - CVE-2026-72326

Vulnerability identifier: #VU143116

CSH Severity: Low

CVSS v4: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-72326

CWE-ID: CWE-191

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause incorrect rate accounting.

The vulnerability exists due to an integer underflow in the CAKE packet length calculation in net/sched/sch_cake.c when processing packets with a negative overhead adjustment. A local user can configure a crafted overhead value to cause incorrect rate accounting.

Exploitation requires the ability to configure CAKE scheduler parameters.

Linux kernel
Ubuntu
linux-nvidia (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)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-nvidia (Ubuntu package) - addressed in versions 5.15.0-1112.113, 5.15.0.1112.112
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

• https://git.kernel.org/stable/c/297f459865360b46a887667cbf3aac6a6f013841
• https://git.kernel.org/stable/c/336c1e414fc0e9844d445174e8ada2a7dd8d1c4b
• https://git.kernel.org/stable/c/7aa0e64fea778a9e3df73e64da95367ff8ad2ea5
• https://git.kernel.org/stable/c/b7f97cae7ec1b6c3c32843c42be218690d310467
• https://git.kernel.org/stable/c/bcdf3a3664f7d2c4e37e155f30f72ef33f041804
• https://git.kernel.org/stable/c/e1df6cff03aad8c96e55a8b2a991e505c7a3ff6f
• https://git.kernel.org/stable/c/f1e7807df5bf2d42a40266430e9f82f37633cdcf
• https://git.kernel.org/stable/c/f511dd7bf6077aa7afbe72914520553fedaacbb4

• Integer underflow in Linux kernel sched
• Ubuntu update for linux-gcp-7.0
• Ubuntu update for linux-nvidia
• Ubuntu update for linux-azure-7.0
• Ubuntu update for linux
• Ubuntu update for linux-azure
• Ubuntu update for linux-oem-7.0