Memory leak in Linux kernel - CVE-2026-98541

Vulnerability identifier: #VU156843

CSH Severity: Low

CVSS v4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98541

CWE-ID: CWE-401

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local privileged user to exhaust kernel memory and cause a denial of service.

The vulnerability exists due to a failure to release packet buffers in the Linux kernel FOU receive handler when a direct encapsulation socket has a zero protocol value. A local privileged user can submit a FOU_CMD_ADD Generic Netlink request with FOU_ATTR_TYPE set to FOU_ENCAP_DIRECT while omitting FOU_ATTR_IPPROTO, then send UDP packets to the resulting socket to leak an sk_buff for each received packet and potentially exhaust kernel memory.

Linux kernel
Ubuntu
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-igx (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-aws (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-nvidia-tegra (Ubuntu package) - update to 5.15.0-1070.72
linux-nvidia-tegra-igx (Ubuntu package) - update to 5.15.0-1059.59
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1070.72~20.04.1
linux (Ubuntu package) - update to 7.0.0-42.42
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17

• https://git.kernel.org/stable/c/3bcc1624cc1cdcc05b566475d6e848093ab2a8f6
• https://git.kernel.org/stable/c/46b1ffb7e169c7e401dd890b29e55dbc261f8f01
• https://git.kernel.org/stable/c/520cf06b8ea0ba5bcc1b8b982ef07f02b5e56221
• https://git.kernel.org/stable/c/7f4ba56f5d310dd018972916167985010a5d66a1
• https://git.kernel.org/stable/c/8b43f40798bb2758489fbbcae7e841ad4443c213
• https://git.kernel.org/stable/c/b1229b210ef5a39c58be665e6798203751411842
• https://git.kernel.org/stable/c/d22609f3d13fc5baacd92c222731b03c593401db
• https://git.kernel.org/stable/c/fd20220f86947d66d4dba2d76f13a28dbd86ef30

• Memory leak in Linux kernel ipv4
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more
• Ubuntu update for linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx
• Ubuntu update for linux, linux-aws, linux-aws-5.15 and more