Out-of-bounds write in Linux kernel - CVE-2026-89761

Vulnerability identifier: #VU149030

CSH Severity: Low

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

CVE-ID: CVE-2026-89761

CWE-ID: CWE-787

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause memory corruption.

The vulnerability exists due to an out-of-bounds write in the AppArmor label vector setup used by aa_label_strn_parse() when parsing label names containing multiple "//&"-separated components. A local user can supply a crafted label name to cause memory corruption.

Every label component must resolve to a loaded profile.

Linux kernel
openEuler
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
kernel-headers
kernel-source
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf
python3-perf-debuginfo

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel - update to 5.10.0-335.0.0.236
bpftool - update to 5.10.0-335.0.0.236
bpftool-debuginfo - update to 5.10.0-335.0.0.236
kernel-debuginfo - update to 5.10.0-335.0.0.236
kernel-debugsource - update to 5.10.0-335.0.0.236
kernel-devel - update to 5.10.0-335.0.0.236
kernel-headers - update to 5.10.0-335.0.0.236
kernel-source - update to 5.10.0-335.0.0.236
kernel-tools - update to 5.10.0-335.0.0.236
kernel-tools-debuginfo - update to 5.10.0-335.0.0.236
kernel-tools-devel - update to 5.10.0-335.0.0.236
perf - update to 5.10.0-335.0.0.236
perf-debuginfo - update to 5.10.0-335.0.0.236
python3-perf - update to 5.10.0-335.0.0.236
python3-perf-debuginfo - update to 5.10.0-335.0.0.236

• https://git.kernel.org/stable/c/28069434aef66b9d084f0609b7a29c171846815e
• https://git.kernel.org/stable/c/36bdd0b45ec3f4822832a56e9db8674c8450dfce
• https://git.kernel.org/stable/c/9124e078ea2250d8d01d2162a550acb01ef5bf48
• https://git.kernel.org/stable/c/9f1e40193eef7f047e6b77cfb4b4cafdecd7a123

• Out-of-bounds write in Linux kernel apparmor include
• openEuler 22.03 LTS SP4 update for kernel