Use-after-free in Linux kernel - CVE-2026-63801

Vulnerability identifier: #VU138856

CSH Severity: Medium

CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-63801

CWE-ID: CWE-416

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to use-after-free in tipc_aead_decrypt_done in the TIPC crypto subsystem when processing crafted encrypted frames during asynchronous decryption. A remote attacker can send crafted encrypted frames to trigger a read from freed memory and cause a denial of service.

Exploitation requires the asynchronous decryption path to be used and can occur while the associated network namespace is being torn down.

Linux kernel
Red Hat Enterprise Linux for Real Time
Red Hat Enterprise Linux for Real Time for NFV
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
Red Hat CodeReady Linux Builder for x86_64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for ARM 64
openEuler
Ubuntu
kernel (Red Hat package)
kernel-rt (Red Hat package)
python3-perf
python3-perf-debuginfo
kernel
perf-debuginfo
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-source
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
kernel-headers
kernel-tools
linux (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel (Red Hat package) - update to 4.18.0-553.162.1.el8_10
kernel-rt (Red Hat package) - update to 4.18.0-553.162.1.rt7.503.el8_10
python3-perf - update to 5.10.0-331.0.0.232
python3-perf-debuginfo - update to 5.10.0-331.0.0.232
kernel - update to 5.10.0-331.0.0.232
perf-debuginfo - update to 5.10.0-331.0.0.232
perf - update to 5.10.0-331.0.0.232
kernel-tools-devel - update to 5.10.0-331.0.0.232
kernel-tools-debuginfo - update to 5.10.0-331.0.0.232
kernel-source - update to 5.10.0-331.0.0.232
bpftool - update to 5.10.0-331.0.0.232
bpftool-debuginfo - update to 5.10.0-331.0.0.232
kernel-debuginfo - update to 5.10.0-331.0.0.232
kernel-debugsource - update to 5.10.0-331.0.0.232
kernel-devel - update to 5.10.0-331.0.0.232
kernel-headers - update to 5.10.0-331.0.0.232
kernel-tools - update to 5.10.0-331.0.0.232
linux (Ubuntu package) - addressed in versions 7.0.0-31.31, 7.0.0-31.31.1, 7.0.0-31.31~24.04.1, 7.0.0-1006.7, 7.0.0-1011.11~24.04.1, 7.0.0-1012.12, 7.0.0-1012.12~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13

• https://git.kernel.org/stable/c/0a780653b2a7569a7af9be7d0b00b1251baca63a
• https://git.kernel.org/stable/c/171d31245d11bf84836fad3b394cb465a4d008ec
• https://git.kernel.org/stable/c/1eea5e1820a2f5164d706bd1277bc97ff31ce32d
• https://git.kernel.org/stable/c/2d1f21419ec121232c916d3a3fc9b6766473a0e7
• https://git.kernel.org/stable/c/bda3348872a2ef0d19f2df6aa8cb5025adce2f20
• https://git.kernel.org/stable/c/dca7713fe044a2067387948557ea099056e1679e
• https://git.kernel.org/stable/c/e18769616fd5a90ec1e12aabbba544c488284292
• https://git.kernel.org/stable/c/eaca7dae02fab70c8d223cffe03cec1b93249ce2

• Use-after-free in Linux kernel tipc
• openEuler 22.03 LTS SP4 update for kernel
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux
• Ubuntu update for linux-gcp-7.0
• Red Hat Enterprise Linux 8 update for kernel-rt
• Red Hat Enterprise Linux 8 update for kernel