CVE-2026-53133 RDMA/umem: Fix truncation for block sizes >= 4G
An integer overflow in the Linux kernel RDMA subsystem allows attackers to compute incorrect DMA addresses, potentially leading to memory corruption or privilege escalation.
- 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-2026-53133?
CVE-2026-53133 is a high-severity 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/umem: Fix truncation for block sizes >= 4G
When the iommu is used the linearization of the mapping can give a single block that is very large split across multiple SG entries.
When __rdma_block_iter_next() reassembles the split SG entries it is overflowing the 32 bit stack values and computed the wrong DMA addresses for blocks after the truncation.
Use the right types to hold DMA addresses.
Which versions are affected by CVE-2026-53133?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53133?
Apply the vendor's patch.
Is CVE-2026-53133 being exploited?
There is no known exploitation of CVE-2026-53133 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-90962, BELL-CVE-2026-53133, DEBIAN-CVE-2026-53133, GHSA-5rwx-cqg3-893x, ROOT-OS-DEBIAN-11-CVE-2026-53133, ROOT-OS-DEBIAN-12-CVE-2026-53133 and 3 more.