CVE-2026-53076 bpf: Fix OOB in pcpu_init_value
An out-of-bounds read in the Linux kernel BPF subsystem allows attackers to read sensitive memory or cause a denial of service.
- 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-2026-53076?
CVE-2026-53076 is a high-severity memory corruption vulnerability in Linux kernel, published on 24 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:
bpf: Fix OOB in pcpu_init_value
An out-of-bounds read occurs when copying element from a BPF_MAP_TYPE_CGROUP_STORAGE map to another pcpu map with the same value_size that is not rounded up to 8 bytes.
The issue happens when: 1. A CGROUP_STORAGE map is created with value_size not aligned to 8 bytes (e.g., 4 bytes) 2. A pcpu map is created with the same value_size (e.g., 4 bytes) 3. Update element in 2 with data in 1
pcpu_init_value assumes that all sources are rounded up to 8 bytes, and invokes copy_map_value_long to make a data copy, However, the assumption doesn't stand since there are some cases where the source may not be rounded up to 8 bytes, e.g., CGROUP_STORAGE, skb->data. the verifier verifies exactly the size that the source claims, not the size rounded up to 8 bytes by kernel, an OOB happens when the source has only 4 bytes while the copy size(4) is rounded up to 8.
Weakness: CWE-125
Which versions are affected by CVE-2026-53076?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53076?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-53076 being exploited?
There is no known exploitation of CVE-2026-53076 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-53076, DEBIAN-CVE-2026-53076, GHSA-645x-23wh-rhvm, ROOT-OS-DEBIAN-11-CVE-2026-53076, ROOT-OS-DEBIAN-12-CVE-2026-53076, ROOT-OS-UBUNTU-2204-CVE-2026-53076 and 2 more.