Look up another CVE · open CVE-2026-90306 in the interactive tracker
CVE-2026-90306
ARM: 9481/2: breakpoint: CFI breakpoints only on demand
Published 2026-09-17 (31 days ago) by the Linux kernel CNA. Subsystem arch/arm. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-90306 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | not affected | 6.1.190-1 | Nothing to do. bookworm never shipped the vulnerable code. |
| Debian 13trixie | vulnerable | 6.12.113-1 | No fix published anywhere yet, neither in Debian nor upstream for the series trixie tracks. Watch the Debian tracker page for this CVE. Advisories for trixie have historically landed a median of 11 days after publication. |
| Debian 14forky | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
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.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
arch/arm/kernel/hw_breakpoint.c
- What this is
- ARM PMU PROFILING AND DEBUGGINGMAINTAINERS section matched on arch/arm*/kernel/hw_breakpoint.c · linux-arm-kernel@lists.infradead.org · Maintained
Check it on the machine
grep -w CONFIG_HAVE_HW_BREAKPOINT /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
Show whether Debian builds this, per release
Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.
- bookwormy
- trixie, forky, sidYnot built on riscv64/riscv64, s390x/s390x
- y
- built into the kernel image on every flavour - only a patch removes it
- Y
- built in where it is built at all; some flavours do not build it
- Build switch
- CONFIG_HAVE_HW_BREAKPOINT
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-09-17 (31 days ago)source
- CVSS
- no vector published, unrated
- Attack vector
- not published
- EPSS
- 0.21%, higher than 10.0% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- Subsystem
- arch/arm
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 6.10 | 6.18.52 | 314f1a6762b5 |
| 6.10 | 7.2.6 | da64b150e4b7 |
| 6.10 | 7.3 | 8ed9bff906cf |
Why the CNA scored it this way
The kernel CNA published no CVSS vector and no reasoning for CVE-2026-90306, which is why it is shown as unrated rather than given an invented score. 6,405 of the 20,413 CVEs here carry reasoning; this is not one of them.