SB20260917176 - Out-of-bounds read in Linux kernel ext4
Published: September 17, 2026
Security Bulletin ID
SB20260917176
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Information disclosure
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Out-of-bounds read (CVE-ID: CVE-2026-89787)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to read out-of-bounds memory.
The vulnerability exists due to an out-of-bounds read in ext4_search_dir() when processing a crafted directory entry during a directory lookup. A local user can provide a crafted directory entry to read out-of-bounds memory.
The issue affects casefolded encrypted directories that store hash values in directory entries on the sb_no_casefold_compat_fallback() path.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/3933884bc3102898b458c53fbd1ac52eb9cdb8a4
- https://git.kernel.org/stable/c/4d20106c536b73c4a8a02652dc85e35898baebf7
- https://git.kernel.org/stable/c/61a395967de06edba58760e81907a272db749faa
- https://git.kernel.org/stable/c/83663c0b739480c00cfe785675db87520ec484ed
- https://git.kernel.org/stable/c/c7e6b863d298f56522d0d08554bbea7f142e6588
- https://git.kernel.org/stable/c/d8c184bec24b5a00ae96d704856d935eaded1685
- https://git.kernel.org/stable/c/e94676a08af6312aa72d8a981232b281f9bcfcf5