Use of Uninitialized Variable in Linux kernel - CVE-2026-68461
Published: August 17, 2026
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to use of uninitialized memory in fwnode_init() in the firmware node handling code when initializing a fwnode_handle allocated on the stack or with a non-zeroing heap allocation. A local user can trigger dereference of an uninitialized secondary pointer to cause a denial of service.
Exploitation requires control over the lifetime and initialization context of the firmware node object.
Affected software
Ubuntu
linux (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-oracle-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-gcp (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-azure (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-nvidia-7.0 (Ubuntu package)
linux-raspi (Ubuntu package)
linux-nvidia-bos (Ubuntu package)
How to mitigate CVE-2026-68461
linux (Ubuntu package) - addressed in versions 5.15.0-195.205~20.04.1, 5.15.0-195.205, 5.15.0-198.208~20.04.1, 5.15.0-198.208+fips1, 5.15.0-1080.84, 5.15.0-1100.108, 5.15.0-1109.111, 5.15.0-1109.114, 5.15.0-1111.115~20.04.1, 5.15.0-1111.115, 5.15.0-1112.118~20.04.1, 5.15.0-1112.118, 5.15.0-1113.119, 5.15.0-1114.120, 5.15.0-1116.125~20.04.1, 5.15.0-1117.124~20.04.1, 5.15.0-1117.124, 5.15.0-1117.124+fips1, 5.15.0-1122.131~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1123.132, 5.15.0-1123.132+fips1, 5.15.0.195.160, 5.15.0.195.205~20.04.1, 5.15.0.198.114, 5.15.0.198.171, 5.15.0.198.208~20.04.1, 5.15.0.1080.83~20.04.1, 5.15.0.1100.99, 5.15.0.1109.105, 5.15.0.1109.113, 5.15.0.1111.108, 5.15.0.1111.115~20.04.1, 5.15.0.1112.111, 5.15.0.1112.118~20.04.1, 5.15.0.1113.112, 5.15.0.1114.110, 5.15.0.1116.120, 5.15.0.1117.113, 5.15.0.1117.120, 5.15.0.1117.124~20.04.1, 5.15.0.1122.131~20.04.1, 5.15.0.1123.107, 5.15.0.1123.121, 5.15.0.1123.132~20.04.1, 7.0.0-31.31~24.04.1, 7.0.0-31.31, 7.0.0-31.31.1, 7.0.0-1006.7, 7.0.0-1011.11~24.04.1, 7.0.0-1012.12~24.04.1, 7.0.0-1012.12
linux-nvidia (Ubuntu package) - addressed in versions 5.15.0-1112.113, 5.15.0.1112.112, 7.0.0-1018.18
linux-oracle-5.15 (Ubuntu package) - addressed in versions 5.15.0-1114.120~20.04.1, 5.15.0.1114.120~20.04.1
linux-gcp-5.15 (Ubuntu package) - addressed in versions 5.15.0-1118.128~20.04.1, 5.15.0.1118.128~20.04.1
linux-gcp (Ubuntu package) - addressed in versions 5.15.0-1118.128, 5.15.0-1118.128+fips1, 5.15.0.1118.107, 5.15.0.1118.115
linux-azure-fde (Ubuntu package) - addressed in versions 5.15.0-1122.131, 5.15.0.1122.131
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1035.38
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1011.11, 7.0.0-1014.14
linux-ibm (Ubuntu package) - update to 7.0.0-1013.13
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
linux-nvidia-7.0 (Ubuntu package) - update to 7.0.0-1018.18~24.04.1
linux-raspi (Ubuntu package) - update to 7.0.0-1019.19
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2018.18
External References
- https://git.kernel.org/stable/c/0198d579948322cda5178b9672d448375a32f947
- https://git.kernel.org/stable/c/173b61c9276c7b3a5fbcc63ae7aafc897fee1e18
- https://git.kernel.org/stable/c/7eba000621fff223dd7bab484d48918c7c77a307
- https://git.kernel.org/stable/c/9c86a1f930bb2ddb85f867b4736716e82a4a4683
- https://git.kernel.org/stable/c/c81e2af41de6a159837c7129a4fc444ac6e48046
- https://git.kernel.org/stable/c/c8542b68ba6ef4f61072098893a3f5b71c569b6c
- https://git.kernel.org/stable/c/f0b4e1cc8ad76baf49d898727eb52e91a4ef0544
Related Security Bulletins
- Use of Uninitialized Variable in Linux kernel fwnode_init() in the firmware node handling code
- Ubuntu update for linux-oem-7.0
- Ubuntu update for linux
- Ubuntu update for linux-gcp-7.0
- Ubuntu update for linux-oracle-7.0
- Ubuntu update for linux-azure
- Ubuntu update for linux-azure-7.0
- Ubuntu update for linux-nvidia
- Ubuntu update for linux-nvidia-bos
- Ubuntu update for linux-ibm
- Ubuntu update for linux-raspi
- Ubuntu update for linux-nvidia-tegra
- Ubuntu update for linux-nvidia-7.0
- Ubuntu update for linux-nvidia
- Ubuntu update for linux-azure-fde
- Ubuntu update for linux-gcp
- Ubuntu update for linux-gcp-5.15
- Ubuntu update for linux-oracle-5.15
- Ubuntu update for linux