Out-of-bounds read in Linux kernel - CVE-2026-98531

Vulnerability identifier: #VU156833

CSH Severity: Low

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

CVE-ID: CVE-2026-98531

CWE-ID: CWE-125

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local privileged user to disclose uninitialized kernel heap memory.

The vulnerability exists due to an out-of-bounds read in the Linux kernel IPv6 segment routing Generic Netlink interface when processing a SEG6_ATTR_DST attribute shorter than an IPv6 address. A local privileged user can send a SEG6_CMD_SET_TUNSRC message containing a zero-length SEG6_ATTR_DST attribute, followed by SEG6_CMD_GET_TUNSRC, to disclose 16 bytes of uninitialized kernel heap memory because the attribute policy enforces only a maximum length while seg6_genl_set_tunsrc() copies a full 16-byte address.

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/050a0aa3c80907b8c60a396b7e04d48d8b1a9e70
• https://git.kernel.org/stable/c/195813bb7324c338eaba0aaa02b18681ee65b670
• https://git.kernel.org/stable/c/209eefebee54c4a5f01d68b61e8ac9881eca2de9
• https://git.kernel.org/stable/c/2d959c75c27f90e9ec489d18ce5ee6b852ad4741
• https://git.kernel.org/stable/c/66bf65fa109326e4c4ddeb0b94093379f72838fd
• https://git.kernel.org/stable/c/6fcfc362344edea745a69f3a705de50b731f3418
• https://git.kernel.org/stable/c/94214cf0a08dd2c5f37aeeea46078d9dfe8e4a0e
• https://git.kernel.org/stable/c/e3ac68c1cdc2535d127b2bfd50c263d16c8e4199

• Out-of-bounds read in Linux kernel ipv6
• 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