CVE-2021-31829: Debian Linux

Medium severity, CVSS 5.5. EPSS: 0.3% chance of exploitation in the next 30 days.

kernel/bpf/verifier.c in the Linux kernel through 5.12.1 performs undesirable speculative loads, leading to disclosure of stack content via side-channel attacks, aka CID-801c6058d14a. The specific concern is not protecting the BPF stack area against speculative loads. Also, the BPF stack can contain uninitialized data that might represent sensitive information previously operated on by the kernel.

Affected products

• Debian Debian Linux: version 9.0 only
• Fedoraproject Fedora: version 32 only; version 33 only; version 34 only
• Linux Linux Kernel: up to and including 5.12.1

Published 2021-05-06. Last modified 2026-06-17.