SB20260912125 - Out-of-bounds read in Linux kernel ceph

Description

This security bulletin contains information about 1 vulnerability.

1) Out-of-bounds read (CVE-ID: CVE-2026-89650)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: 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]

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.

Remediation

Install update from vendor's website.

References

• 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