Use-after-free in Linux kernel - CVE-2026-98571

Vulnerability identifier: #VU156874

CSH Severity: Low

CVSS v4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98571

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause memory corruption that may result in a denial of service.

The vulnerability exists due to use-after-free in the Linux kernel stmmac receive path when napi_build_skb() fails during packet reception. The recycled page remains referenced by buf->page, causing stmmac_rx_refill() to skip replacement allocation and program the already-recycled page into an RX descriptor. A local user can exploit this stale page reference to potentially corrupt kernel memory and cause 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/0a7822e34a0bfde31b194ac3da3253e5032b44cc
• https://git.kernel.org/stable/c/298673397ea3f6f5811b84f0d9f71eac71dda2e3
• https://git.kernel.org/stable/c/501baaeca7d128fa0a2f6953cf5873c5b0d7cf89

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