CVE-2026-80723 of: reserved_mem: prevent OOB when too many dynamic regions are defined
A missing bounds check in the Linux kernel's reserved memory scanner allows out-of-bounds writes if too many dynamic regions are defined, potentially causing crashes or code execution.
- 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-2026-80723?
CVE-2026-80723 is a high-severity memory corruption vulnerability in Linux, published on 28 Aug 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:
of: reserved_mem: prevent OOB when too many dynamic regions are defined
On boot, fdt_scan_reserved_mem() saves each dynamically-placed /reserved-memory subnode into a local array of size MAX_RESERVED_REGIONS.
If the device tree defines more than MAX_RESERVED_REGIONS dynamically-placed regions, fdt_scan_reserved_mem() writes past the end of the local array.
Add a bounds check that logs an error and skips the excess regions, restoring the original behavior.
Which versions are affected by CVE-2026-80723?
How do I fix CVE-2026-80723?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-80723 being exploited?
There is no known exploitation of CVE-2026-80723 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-80723, DEBIAN-CVE-2026-80723, GHSA-m4gx-g2g6-vwmj, UBUNTU-CVE-2026-80723.