CVE-2026-74733 gpio: pca953x: fix pca953x_irq_bus_sync_unlock regmap lock
A race condition in the PCA953x GPIO driver allows concurrent threads to corrupt register states due to missing locks.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-74733?
CVE-2026-74733 is a high-severity vulnerability in Linux, published on 22 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:
gpio: pca953x: fix pca953x_irq_bus_sync_unlock regmap lock
Locking is disabled in the regmap config as this driver uses its own lock. This means that all calls to regmap functions (read or write) must hold the i2c_lock. The function pca953x_irq_bus_sync_unlock() did not do this, and it was therefore possible that multiple threads could cause an incorrect register to be read/written.
A previous patch partly fixed this, but only protected the write to the interrupt mask register, and not the read from the direction register.
Which versions are affected by CVE-2026-74733?
How do I fix CVE-2026-74733?
Apply the vendor's patch.
Is CVE-2026-74733 being exploited?
There is no known exploitation of CVE-2026-74733 in the wild and no public exploit code.
Sources
Also known as AZL-97329, BELL-CVE-2026-74733, DEBIAN-CVE-2026-74733, GHSA-p6rq-qpqh-5f25, UBUNTU-CVE-2026-74733.