CVE-2021-4159: Debian Linux

Medium severity, CVSS 4.4. EPSS: 0.2% chance of exploitation in the next 30 days.

A vulnerability was found in the Linux kernel's EBPF verifier when handling internal data structures. Internal memory locations could be returned to userspace. A local attacker with the permissions to insert eBPF code to the kernel can use this to leak internal kernel memory details defeating some of the exploit mitigations in place for the kernel.

Affected products

• Debian Debian Linux: version 10.0 only
• Linux Linux Kernel: before 5.7 (fixed in 5.7)
• Red Hat Enterprise Linux: version 8.0 only

Published 2022-08-24. Last modified 2026-06-17.