CVE-2021-31829 Information disclosure in n/a

What is CVE-2021-31829?

CVE-2021-31829 is a medium-severity vulnerability in Debian Debian Linux, published on 6 May 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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.

Weakness: CWE-863

Which versions are affected by CVE-2021-31829?

It affects 3 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Linux kernel.

How do I fix CVE-2021-31829?

Apply the vendor's patch.

Is CVE-2021-31829 being exploited?

There is no known exploitation of CVE-2021-31829 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-6557, DEBIAN-CVE-2021-31829, GHSA-f8g9-h6rj-mq5j, UBUNTU-CVE-2021-31829.