In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix OOB in pcpuinitvalue
An out-of-bounds read occurs when copying element from a BPFMAPTYPECGROUPSTORAGE map to another pcpu map with the same value_size that is not rounded up to 8 bytes.
The issue happens when: 1. A CGROUPSTORAGE map is created with valuesize 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
pcpuinitvalue assumes that all sources are rounded up to 8 bytes, and invokes copymapvaluelong 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., CGROUPSTORAGE, 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.
{
"cna_assigner": "Linux",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53076.json"
}