Out-of-bounds read in Linux kernel - CVE-2026-90170
Published: September 19, 2026
Vulnerability details
The vulnerability allows a local user to read memory out of bounds.
The vulnerability exists due to an out-of-bounds read in the ksmbd ipc_validate_msg() function when processing undersized IPC responses supplied by the userspace ksmbd daemon. A local user can provide a short IPC response to read memory out of bounds.
The issue is reachable for KSMBD_EVENT_RPC_REQUEST messages.
Affected software
Debian Linux
Ubuntu
linux-nvidia-tegra (Ubuntu package)
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)
How to mitigate CVE-2026-90170
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 6.12.111-1
External References
- https://git.kernel.org/stable/c/0aa8f94bfd4d818284c8a7ce0040d40ca1ec3595
- https://git.kernel.org/stable/c/17b7d1a2b4d5473df5dca8c9a07d65021806c23a
- https://git.kernel.org/stable/c/398cba4b646a6c08ff3d79e6b1e70e5ddae8a065
- https://git.kernel.org/stable/c/c494fcf8e89e3c970e13d78ebe62bf5d8f2b1c52
- https://git.kernel.org/stable/c/e9b33376bd07bca4175f7bcc2d6034ef250f8181