NULL pointer dereference in Linux kernel - CVE-2026-43424
Published: May 8, 2026
Vulnerability details
The vulnerability allows an attacker with physical access to cause a denial of service.
The vulnerability exists due to a NULL pointer dereference in the USB Target driver f_tcm BOT command and request processing paths when handling crafted Bulk-Only Transport commands during a race window where the nexus is not established or has just been dropped. An attacker with physical access can send a specially crafted USB request to cause a denial of service.
The issue occurs if requests arrive before the nexus is fully established or immediately after it is dropped.
Affected software
Ubuntu
linux (Ubuntu package)
linux-fips (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oracle-6.8 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-aws (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-gcp-fips (Ubuntu package)
How to mitigate CVE-2026-43424
linux (Ubuntu package) - addressed in versions 6.8.0-136.136, 6.8.0-1046.50, 6.8.0-1059.67, 6.8.0-1064.72, 6.8.0-1064.72~22.04.1, 6.8.1-1056.57, 6.8.1-1056.57~22.04.2
linux-fips (Ubuntu package) - addressed in versions 6.8.0-136.136+fips2, 6.8.0-136.136.2, 6.8.0-136.136.2~22.04.1, 6.8.0-1058.61
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-1030.31, 6.8.0-1033.34, 6.8.0-1061.62, 6.8.0-1061.62~22.04.1
linux-oracle-6.8 (Ubuntu package) - update to 6.8.0-1058.61~22.04.1
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1059.62, 6.8.0-1059.62.1, 6.8.0-1059.62~22.04.1
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1061.64+fips1, 6.8.0-1061.64~22.04.1
linux-aws (Ubuntu package) - update to 6.8.0-1061.64+1
linux-azure-fde (Ubuntu package) - update to 6.8.0-1062.69
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1063.71, 6.8.0-1063.71~22.04.1
linux-azure-fips (Ubuntu package) - update to 6.8.0-1063.71+fips2
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1064.72+fips1
External References
- https://git.kernel.org/stable/c/2a2ef846a54a06c33b5c2d4b0d918583e1e7c0b7
- https://git.kernel.org/stable/c/3d309b37633c4a847fc149939a2c9576f1aa1065
- https://git.kernel.org/stable/c/679d9535aeb15c10bce89c44102004b96624d706
- https://git.kernel.org/stable/c/b9b26d7f3aa288cfa54a7bc68612bab1f153f156
- https://git.kernel.org/stable/c/b9fde507355342a2d64225d582dc8b98ff5ecb19
- https://git.kernel.org/stable/c/d146f27758049fa55ae4c53785a852d3cf7a18d6
- https://git.kernel.org/stable/c/f962ca3b020e13d6714f27e8c36fe742441c58d1
Related Security Bulletins
- NULL pointer dereference in Linux kernel gadget function driver
- Ubuntu update for linux
- Ubuntu update for linux-gcp-fips
- Ubuntu update for linux-oracle-6.8
- Ubuntu update for linux-fips
- Ubuntu update for linux-nvidia
- Ubuntu update for linux-azure-fde-6.8
- Ubuntu update for linux-azure-fips
- Ubuntu update for linux-azure-fde
- Ubuntu update for linux-azure
- Ubuntu update for linux-aws
- Ubuntu update for linux-hwe-6.8
- Ubuntu update for linux-aws-6.8
- Ubuntu update for linux-ibm