Out-of-bounds read in Linux kernel - CVE-2026-89787
Published: September 17, 2026
Vulnerability identifier: #VU150498
CSH Severity: Low
CVSS v4: 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]
CVE-ID: CVE-2026-89787
CWE-ID: CWE-125
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
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.
Affected software
Linux kernel
How to mitigate CVE-2026-89787
Install security update from vendor's repository.
External 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