CVE-2026-90306 ARM: 9481/2: breakpoint: CFI breakpoints only on demand
Fixes ARM kernel breakpoint handling to prevent interference with userspace breakpoints when CFI is disabled, ensuring correct fault reporting.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-90306?
CVE-2026-90306 is a vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ARM: 9481/2: breakpoint: CFI breakpoints only on demand
This removes the stub hw_breakpoint_cfi_handler() from ARM, making it not steal breakpoint type 0x03 (ARM_ENTRY_CFI_BREAKPOINT) unless CFI is actively used in the kernel.
When not instrumenting with CFI, or when a breakpoint is issued in userspace, we fall through to return 1 from hw_breakpoint_pending() "unhandled fault" so userspace can make use of this breakpoint.
Tested with LKDTM and this command line: echo CFI_FORWARD_PROTO > /sys/kernel/debug/provoke-crash/DIRECT still works as expected.
Which versions are affected by CVE-2026-90306?
How do I fix CVE-2026-90306?
Apply the vendor's patch.
Is CVE-2026-90306 being exploited?
There is no known exploitation of CVE-2026-90306 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-90306, DEBIAN-CVE-2026-90306, GHSA-83wp-8ph8-8m42, UBUNTU-CVE-2026-90306.