CVE-2026-53400 i2c: core: fix adapter registration race
A race condition in the Linux kernel i2c core allows attackers to trigger NULL-pointer dereferences or use-after-free errors, causing system crashes.
- 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-2026-53400?
CVE-2026-53400 is a high-severity vulnerability in Linux kernel, published on 19 Jul 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:
i2c: core: fix adapter registration race
Adapters can be looked up based on their id using i2c_get_adapter() which takes a reference to the embedded struct device.
Make sure that the adapter (including its struct device) has been initialised before adding it to the IDR to avoid accessing uninitialised data which could, for example, lead to NULL-pointer dereferences or use-after-free.
Note that the i2c-dev chardev, which is registered from a bus notifier, currently uses i2c_get_adapter() so the adapter needs to be added to the IDR before registration.
Weakness: CWE-362
Which versions are affected by CVE-2026-53400?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53400?
Apply the vendor's patch.
Is CVE-2026-53400 being exploited?
There is no known exploitation of CVE-2026-53400 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-92564, BELL-CVE-2026-53400, DEBIAN-CVE-2026-53400, GHSA-9p96-44q4-p2j5, ROOT-OS-DEBIAN-11-CVE-2026-53400, ROOT-OS-DEBIAN-12-CVE-2026-53400 and 2 more.