Improper input validation in Linux kernel - CVE-2026-98569

Vulnerability identifier: #VU156872

CSH Severity: Low

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

CVE-ID: CVE-2026-98569

CWE-ID: CWE-20

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local privileged user to cause a denial of service by disrupting metadata receive lookup for GRE, GRETAP, or ERSPAN tunnel devices.

The vulnerability exists due to missing validation of metadata tunnel uniqueness in ipgre_netlink_parms() when enabling collect_md on an existing tunnel device through changelink. A local privileged user can convert a non-metadata device to metadata mode, replacing another device's metadata receive entry of the same type in the same network namespace, and then delete either device to disrupt metadata receive lookup for the surviving device.

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/1dc759571f3df14891175fc52527f7624ba01322
• https://git.kernel.org/stable/c/2e54d53b65e296b4b4bdc2cdd3b2b58dfa8d8c5c
• https://git.kernel.org/stable/c/63c5e48d6f7f5722a48f63e13e961dc5302894ed
• https://git.kernel.org/stable/c/a3f315be9d30eeb6938d11fa17fd4b32d52f7c42
• https://git.kernel.org/stable/c/bdd41b96e814300c66222cf4e47ecb8aef995656
• https://git.kernel.org/stable/c/c80315da84998b69b8829785a174b0bf72a81992
• https://git.kernel.org/stable/c/cff8b520312e750ad38967c30128e1534cbf9484
• https://git.kernel.org/stable/c/da2e0cfbb620b199927a1e5b93b7cfde32083c7d

• Improper input validation 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