Unisoc kernel DVFS driver flaw (CVE-2026-87765): fixed

What the vulnerability is

Unisoc reports that its kernel APsys DVFS driver, which manages processor power and frequency, does not properly validate a frequency index. That can cause an out-of-bounds read or corrupt a hardware register, leading to system instability or denial of service. Unisoc rates it 5.5 (Medium): it needs local access and some privileges, and it affects availability only, not data. Its affected chips include the T7200, the current name of the T606 in OhrTech devices.

How it affected OhrTech devices

The Foundation OS kernel includes this driver, ported from Unisoc's code, so the flaw was present. On OhrTech devices only a privileged system process allowed by our SELinux policy could reach it; apps and the shell cannot. The worst outcome was a crash or instability, not access to data. We know of no exploitation, and the U.S. Cybersecurity and Infrastructure Security Agency's assessment records none.

What we did

We fixed the flaw in the Foundation OS kernel. While reviewing the same driver, we found a related local denial-of-service in it, introduced when the driver was ported, and fixed that too. Both fixes are in Foundation OS release 2026101902, released on October 19, 2026.

This update does not change the security patch level, which stays at 2026-10-01. To tell whether a device has the fix, check its Foundation OS release, not its patch level.

Who needs to act

If you approve updates manually, approve release 2026101902 or later. Devices on release 2026101901 or earlier still have the flaw until they take it.

Credit

Unisoc disclosed this flaw in its October 2026 security bulletin and did not name who found it.