Out-of-bounds read in Linux kernel - CVE-2026-90161

Vulnerability identifier: #VU151320

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-90161

CWE-ID: CWE-125

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to disclose sensitive information.

The vulnerability exists due to improper validation of interlaced ztailpacking pclusters in the EROFS decompression and block-mapping code when processing a crafted EROFS filesystem image. A local user can process an image containing invalid interlaced ztailpacking pclusters to disclose sensitive information.

Existing valid filesystems are not affected.

Linux kernel
Debian Linux
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux (Debian package)

Install security update from vendor's repository.

linux (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17
linux (Debian package) - update to 6.12.115-2

• https://git.kernel.org/stable/c/451027c642e752420e1a04237db9ce7b35cee595
• https://git.kernel.org/stable/c/862427ebb81d1f6abbf74d799790e1694b37b187
• https://git.kernel.org/stable/c/ddb7ea4fd99bf6c4314d1dfca18aec6945ce8054

• Out-of-bounds read in Linux kernel erofs
• Debian update for linux
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more