Out-of-bounds read in Linux kernel - CVE-2026-89650

Vulnerability identifier: #VU149148

CSH Severity: Low

CVSS v4: 0 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-89650

CWE-ID: CWE-125

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause an out-of-bounds read in the kernel.

The vulnerability exists due to an out-of-bounds read in ceph_mdsmap_decode() in fs/ceph/mdsmap.c when processing an MDS map with a per-mds info version of 2 or 3 and an oversized num_export_targets field. A remote attacker can send a specially crafted MDS map to cause an out-of-bounds read in the kernel.

On-path exploitation applies to unsigned or unencrypted messenger sessions.

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/332c444f4dc6fa1e8b8637c9e82d29e97f768656
• https://git.kernel.org/stable/c/3bf7dba8dba9a05774b846affec61a3624ddba38
• https://git.kernel.org/stable/c/58c2d3e954c13694ef6e820a5e9456461bb9e7df
• https://git.kernel.org/stable/c/a3eb169ee297aa99670ba927c659990bd1e453f3

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