Improper Initialization in Linux kernel - CVE-2026-43184
Published: May 7, 2026
Vulnerability details
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to improper initialization in rnbd-srv response buffer handling when exchanging response messages between different protocol versions. A remote attacker can trigger communication using mismatched protocol versions to disclose sensitive information.
The issue arises because stray bytes in the response buffer may be picked up by the client side.
Affected software
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux-intel-iot-realtime (Ubuntu package)
linux-ibm-5.15 (Ubuntu package)
linux-intel-iotg (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-5.15 (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-raspi (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-raspi-realtime (Ubuntu package)
How to mitigate CVE-2026-43184
linux (Ubuntu package) - addressed in versions 5.15.0.184.155, 5.15.0-184.194, 5.15.0-184.194~20.04.1, 5.15.0.186.166, 5.15.0-186.196, 5.15.0-186.196~20.04.1, 5.15.0.1075.78, 5.15.0-1075.79, 5.15.0.1095.94, 5.15.0-1095.103, 5.15.0.1104.100, 5.15.0-1104.109, 5.15.0.1108.107, 5.15.0-1108.114, 5.15.0.1111.115, 5.15.0-1111.120+fips1, 5.15.0.1112.102, 5.15.0.1112.109, 5.15.0-1112.122, 5.15.0-1112.122+fips1, 6.8.0-134.134, 6.8.0-1057.58~22.04.1, 6.8.0-1058.61+fips1, 6.8.0-1058.61~22.04.1, 6.8.0-1060.61, 6.8.0-1060.63+fips1, 6.8.0-1060.63~22.04.1, 6.8.0-1063.69, 6.8.0-1063.69+fips1, 6.8.1-1055.56, 6.8.1-1055.56~22.04.1
linux-aws (Ubuntu package) - addressed in versions 5.15.0.186.109, 5.15.0-186.196+fips1, 5.15.0.1106.103, 5.15.0-1106.110, 5.15.0.1107.107, 5.15.0-1107.108, 5.15.0.1112.108, 5.15.0.1112.115, 5.15.0-1112.119, 5.15.0-1112.119+fips1, 5.15.0-1112.119~20.04.1
linux-nvidia-tegra (Ubuntu package) - addressed in versions 5.15.0-1053.53, 5.15.0.1053.55, 5.15.0.1064.64, 5.15.0-1064.66, 6.8.0-1029.30
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1064.66~20.04.1
linux-intel-iot-realtime (Ubuntu package) - addressed in versions 5.15.0-1104.106, 5.15.0.1104.108, 5.15.0-1107.113~20.04.1
linux-ibm-5.15 (Ubuntu package) - update to 5.15.0-1106.110~20.04.1
linux-intel-iotg (Ubuntu package) - addressed in versions 5.15.0.1107.106, 5.15.0-1107.113
linux-azure (Ubuntu package) - addressed in versions 5.15.0.1109.105, 5.15.0-1109.115, 5.15.0.1117.115, 5.15.0-1117.126, 6.8.0-1063.71, 6.8.0-1063.71~22.04.1
linux-azure-5.15 (Ubuntu package) - addressed in versions 5.15.0-1109.115~20.04.1, 5.15.0-1117.126~20.04.1, 5.15.0-1117.126~20.04.2
linux-azure-fips (Ubuntu package) - addressed in versions 5.15.0.1117.102, 5.15.0-1117.126+fips1, 6.8.0-134.134+fips1, 6.8.0-1062.69+fips1
linux-azure-fde (Ubuntu package) - addressed in versions 5.15.0-1117.126, 6.8.0-1062.69
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1045.48, 6.8.0-1057.58~22.04.1, 6.8.0-1058.61.1, 6.8.0-1058.64, 6.8.0-1060.61~22.04.1, 6.8.0-1060.63~22.04.1, 6.8.0-1063.69~22.04.1
linux-raspi (Ubuntu package) - update to 6.8.0-1060.64
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-raspi-realtime (Ubuntu package) - update to 6.8.0-2049.50
External References
- https://git.kernel.org/stable/c/30868a6a5238849d554295aff3ce61d242d7fad8
- https://git.kernel.org/stable/c/69d26698e4fd44935510553809007151b2fe4db5
- https://git.kernel.org/stable/c/7aac0a30dcf41cdb510526740d9a2ab1520c5d98
- https://git.kernel.org/stable/c/852475278ca5e96e0c0275950e1a84203e602b33
- https://git.kernel.org/stable/c/b646e54d23b9b592d612a2036aab14e0f6c14206
- https://git.kernel.org/stable/c/c94ede3c436dfbd9cedd9cb69f604f6fc901b6a2
- https://git.kernel.org/stable/c/e2cacec7d4291300a282feb3af8eba57b93b15aa
- https://git.kernel.org/stable/c/e4272754063d52c9ad0169865add8816ba696471
Related Security Bulletins
- Improper Initialization in Linux kernel block rnbd driver
- Ubuntu update for linux
- Ubuntu update for linux-nvidia-tegra
- Ubuntu update for linux-aws-6.8
- Ubuntu update for linux-raspi-realtime
- Ubuntu update for linux-raspi
- Ubuntu update for linux-azure-fips
- Ubuntu update for linux-nvidia-tegra-5.15
- Ubuntu update for linux
- Ubuntu update for linux-ibm-5.15
- Ubuntu update for linux-nvidia-tegra
- Ubuntu update for linux-aws
- Ubuntu update for linux-azure-fde
- Ubuntu update for linux-azure
- Ubuntu update for linux-azure-fde-6.8
- Ubuntu update for linux-azure-fde
- Ubuntu update for linux-azure
- Ubuntu update for linux-azure-5.15
- Ubuntu update for linux-hwe-6.8
- Ubuntu update for linux-azure-fips
- Ubuntu update for linux-intel-iot-realtime
- Ubuntu update for linux-intel-iotg