Improper resource shutdown or release in Linux kernel - CVE-2026-52996
Published: June 25, 2026
Vulnerability details
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to improper resource shutdown or release in parse_durable_handle_context() in the ksmbd SMB server durable handle processing when handling durable v2 open requests with a matching CreateGuid but mismatched ClientGUID. A remote user can send specially crafted durable reconnect requests to cause a denial of service.
Repeated mismatch requests can pin global file table entries and prevent file cleanup for the corresponding files.
Affected software
Ubuntu
linux (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure (Ubuntu package)
linux-aws (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-bos (Ubuntu package)
How to mitigate CVE-2026-52996
linux (Ubuntu package) - addressed in versions 7.0.0-28.28, 7.0.0-28.28.1, 7.0.0-1003.4, 7.0.0-1008.8
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1009.9
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
linux-nvidia (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1016.16~24.04.1
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16
External References
- https://git.kernel.org/stable/c/06f709d0e531f3e54d88665dd426be3998a774e6
- https://git.kernel.org/stable/c/407b6e699ba8b45b72cc265eed8a1bc8a7191609
- https://git.kernel.org/stable/c/804054d19886ac6628883d82410f6ee42a818664
- https://git.kernel.org/stable/c/8c4a0ef19c8264c150833131af34541495832cd0
- https://git.kernel.org/stable/c/f31beef633fbf2b5af7805fa187a10bcff1d4b49