Improper Validation of Specified Quantity in Input in Linux kernel - CVE-2026-98556

Vulnerability identifier: #VU156860

CSH Severity: Low

CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98556

CWE-ID: CWE-1284

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause oversized packets to reach a network device, potentially disrupting packet transmission.

The vulnerability exists due to insufficient packet-size validation in the Linux kernel's layer 2 forwarding path when forwarding GSO packets that subsequently undergo software segmentation. A local user can supply packets with an oversized gso_size through a tap interface or packet socket to produce non-TSO packets exceeding the device's supported packet size, potentially disrupting packet transmission.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (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 (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
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/296c83b5ccc808c080865eb20fd7a477b0355bb7
• https://git.kernel.org/stable/c/2dc3ae3942e151fef254b7bbb65c832192ad2069
• https://git.kernel.org/stable/c/c517e8755960c8c6335ebf7dae6c95c43e5fb085

• Improper Validation of Specified Quantity in Input in Linux kernel google gve driver
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more