Out-of-bounds write in Linux kernel - CVE-2026-89652

Vulnerability identifier: #VU149150

CSH Severity: Low

CVSS v4: 2.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-89652

CWE-ID: CWE-787

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote user to cause memory corruption.

The vulnerability exists due to improper bounds checking in the CephFS NFS-export get_name functions when processing LOOKUPNAME replies containing oversized dentry names. A remote user can return a specially crafted LOOKUPNAME reply to cause memory corruption.

The issue is reachable when a CephFS mount is re-exported over NFS.

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.

kernel - update to 5.10.0-334.0.0.235
bpftool - update to 5.10.0-334.0.0.235
bpftool-debuginfo - update to 5.10.0-334.0.0.235
kernel-debuginfo - update to 5.10.0-334.0.0.235
kernel-debugsource - update to 5.10.0-334.0.0.235
kernel-devel - update to 5.10.0-334.0.0.235
kernel-headers - update to 5.10.0-334.0.0.235
kernel-source - update to 5.10.0-334.0.0.235
kernel-tools - update to 5.10.0-334.0.0.235
kernel-tools-debuginfo - update to 5.10.0-334.0.0.235
kernel-tools-devel - update to 5.10.0-334.0.0.235
perf - update to 5.10.0-334.0.0.235
perf-debuginfo - update to 5.10.0-334.0.0.235
python3-perf - update to 5.10.0-334.0.0.235
python3-perf-debuginfo - update to 5.10.0-334.0.0.235

• https://git.kernel.org/stable/c/06fb5e623cdc2402d6bb29be94d9beb9a826ffec
• https://git.kernel.org/stable/c/61d9f27b191b838b96b697ce0bfaee39a138243a
• https://git.kernel.org/stable/c/e7c2fd3893a7f7fcd7e8cf0b2c6348bb1e893df6
• https://git.kernel.org/stable/c/eff8013c5a8916613c742ae5a2cc341cb605c0ae

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