Out-of-bounds read in Linux kernel - CVE-2026-89778
Published: September 17, 2026
Vulnerability identifier: #VU150504
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89778
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to read memory out of bounds.
The vulnerability exists due to an out-of-bounds read in zisofs_fill_pages() when reading a compressed file on a mounted ISO9660 image containing a crafted ZF Rock Ridge record. A remote attacker can provide a crafted ISO9660 image to read memory out of bounds.
The issue is triggered when an empty zisofs block follows a sub-page block with a nonzero page offset.
Affected software
Linux kernel
How to mitigate CVE-2026-89778
Install security update from vendor's repository.
External References
- https://git.kernel.org/stable/c/68d4d3e78150c7ed7d1195af63ad1e6ace30c661
- https://git.kernel.org/stable/c/85904076cece72ee3194646ad7ac8e6659d999aa
- https://git.kernel.org/stable/c/8b994ac5778a725982fd6a8a3afcaa068d4a93e3
- https://git.kernel.org/stable/c/9c6eace8d07e90f038c89eb3b756d65a7e259d48
- https://git.kernel.org/stable/c/ad3249cdf9d4ba34bb8b1ff3956a4020fdfb5b0a
- https://git.kernel.org/stable/c/cd616aa0449a772a6956abf03358f0ff31720580
- https://git.kernel.org/stable/c/f03425dcbe04aec3c27b9917e97d7d23a2908dda