Use-after-free in Linux kernel - CVE-2026-98503

Vulnerability identifier: #VU156804

CSH Severity: Low

CVSS v4: 5.8 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98503

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to potentially corrupt packet data or cause a denial of service.

The vulnerability exists due to premature release of transmit-ring slots in the Linux kernel packet socket transmit path when skb_orphan invokes a packet buffer's destructor while the buffer still references ring-slot payload data. A local user can exercise the TX_RING transmission path to trigger reuse of a slot still referenced by an in-flight packet, potentially corrupting packet data or causing a denial of service.

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/2a0c9afefc0ecea2cc30ccfbbbc98182a0986191
• https://git.kernel.org/stable/c/9518405613863d0bf0700927a21367f5942cf058
• https://git.kernel.org/stable/c/e67c455d79fbf709a94965f09a2be6bf4f4ba5fd
• https://git.kernel.org/stable/c/eda9bcb721f15a93746a99eabda33d80b86404fd

• Use-after-free in Linux kernel packet
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more