Use of Uninitialized Variable in Linux kernel - CVE-2026-53134

Vulnerability identifier: #VU135654

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-53134

CWE-ID: CWE-457

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to disclose sensitive information.

The vulnerability exists due to uninitialized memory exposure in the nft_fib IPv4/IPv6 evaluation logic when processing nftables fib expressions that use the OIFNAME result or an invalid NFTA_FIB_F_PRESENT combination. A local user can configure and trigger a crafted fib expression to disclose sensitive information.

The issue occurs because only part of the declared destination register span is written on certain evaluation paths, leaving stale kernel stack data available to a downstream expression that reads the full register span.

Linux kernel
openEuler
Ubuntu
bpftool
python3-perf-debuginfo
python3-perf
perf-debuginfo
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-tools
kernel-source
kernel-headers
kernel-devel
kernel-debugsource
kernel-debuginfo
bpftool-debuginfo
kernel
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
bpftool - update to 6.6.0-145.1.20.157
python3-perf-debuginfo - update to 6.6.0-145.1.20.157
python3-perf - update to 6.6.0-145.1.20.157
perf-debuginfo - update to 6.6.0-145.1.20.157
perf - update to 6.6.0-145.1.20.157
kernel-tools-devel - update to 6.6.0-145.1.20.157
kernel-tools-debuginfo - update to 6.6.0-145.1.20.157
kernel-tools - update to 6.6.0-145.1.20.157
kernel-source - update to 6.6.0-145.1.20.157
kernel-headers - update to 6.6.0-145.1.20.157
kernel-devel - update to 6.6.0-145.1.20.157
kernel-debugsource - update to 6.6.0-145.1.20.157
kernel-debuginfo - update to 6.6.0-145.1.20.157
bpftool-debuginfo - update to 6.6.0-145.1.20.157
kernel - update to 6.6.0-145.1.20.157
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/3544210609f6d1db282bbdeca639104ef624c393
• https://git.kernel.org/stable/c/6744e49fe51bfba26522acc2d0e9703cb41d8e50
• https://git.kernel.org/stable/c/84d8f58cf28a0415413f43ba7148f7bacd4c1b6e
• https://git.kernel.org/stable/c/8c84885e9790823828bb8084736ea15769b1ac16
• https://git.kernel.org/stable/c/ab185e0c4fb82dfba6fb86f8271e06f931d9c64c
• https://git.kernel.org/stable/c/d19ddef8c327a4773ff81f8e51027d1e0b4cf069
• https://git.kernel.org/stable/c/eb8a8124484dbc3c2b543e207da39bbccb703d31
• https://git.kernel.org/stable/c/eca18feed38b3377a2ec5d1f22af1170c55d0171

• Use of Uninitialized Variable in Linux kernel netfilter
• openEuler 24.03 LTS SP1 update for kernel
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux
• Ubuntu update for linux-gcp-7.0