Double free in Linux kernel - CVE-2026-64054

Vulnerability identifier: #VU138595

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-2026-64054

CWE-ID: CWE-415

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a double free in net_shaper_nl_group_doit() when processing a GROUP request with duplicate NET_SHAPER_A_LEAVES entries. A local user can supply the same leaf handle twice to cause a denial of service.

The issue occurs when multiple supplied leaves reference the same parent, causing the same old-parent pointer to be stored twice in the cleanup list.

Linux kernel
Ubuntu
linux-ibm (Ubuntu package)
linux-azure (Ubuntu package)
linux-aws (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
linux-nvidia (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1016.16~24.04.1
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16

• https://git.kernel.org/stable/c/31767bf852b59f05125b58a17007e4cd1ea9eb2e
• https://git.kernel.org/stable/c/5098b223f0f0c5c18a3884a8b0ea5bd4a0c7bd75
• https://git.kernel.org/stable/c/a9a2fa1da619f276580b0d4c5d12efac89e8642b

• Double free in Linux kernel shaper
• Ubuntu update for linux-ibm
• Ubuntu update for linux-azure
• Ubuntu update for linux-aws
• Ubuntu update for linux-nvidia-bos
• Ubuntu update for linux-nvidia