CVE-2026-53188 RDMA/core: Validate the passed in fops for ib_get_ucaps()
Attackers can masquerade as RDMA userspace clients by spoofing device file descriptors, bypassing authentication checks in the Linux kernel.
- 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-2026-53188?
CVE-2026-53188 is a high-severity authentication bypass vulnerability in Linux kernel, published on 25 Jun 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:
RDMA/core: Validate the passed in fops for ib_get_ucaps()
Sashiko pointed out it is not safe to rely only on the devt because char/block alias so if the user finds a block device with the same dev_t it can masquerade as a ucap cdev fd.
Test the f_ops to only accept authentic cdevs.
Weakness: CWE-285
Which versions are affected by CVE-2026-53188?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53188?
Apply the vendor's patch.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-53188 being exploited?
There is no known exploitation of CVE-2026-53188 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-53188, DEBIAN-CVE-2026-53188, GHSA-4rj2-pr7f-cmpg, UBUNTU-CVE-2026-53188.