SB20260912130 - Use-after-free in Linux kernel ceph
Published: September 12, 2026
Security Bulletin ID
SB20260912130
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Information disclosure
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use-after-free (CVE-ID: CVE-2026-89655)
CWE-ID: CWE-416 - Use After Free
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 trigger a use-after-free condition.
The vulnerability exists due to use-after-free in __kick_flushing_caps() when processing FLUSH_ACK messages during cap flushing. A remote attacker can send a FLUSH_ACK message during cap flushing to trigger a use-after-free condition.
Exploitation requires the FLUSH_ACK to be processed after i_ceph_lock is released and before list iteration resumes.
Remediation
Install update from vendor's website.