CVE-2023-3776: Debian Linux

High severity, CVSS 7.8. EPSS: 0.5% chance of exploitation in the next 30 days.

A use-after-free vulnerability in the Linux kernel's net/sched: cls_fw component can be exploited to achieve local privilege escalation. If tcf_change_indev() fails, fw_set_parms() will immediately return an error after incrementing or decrementing the reference counter in tcf_bind_filter(). If an attacker can control the reference counter and set it to zero, they can cause the reference to be freed, leading to a use-after-free vulnerability. We recommend upgrading past commit 0323bce598eea038714f941ce2b22541c46d488f.

Affected products

• Debian Debian Linux: version 10.0 only; version 11.0 only; version 12.0 only
• Linux Linux Kernel: from 2.6.12, before 4.14.322 (fixed in 4.14.322); from 4.15, before 4.19.291 (fixed in 4.19.291); from 4.20, before 5.4.251 (fixed in 5.4.251); from 5.5, before 5.10.188 (fixed in 5.10.188); from 5.11, before 5.15.121 (fixed in 5.15.121); from 5.16, before 6.1.40 (fixed in 6.1.40); …

Published 2023-07-21. Last modified 2026-06-17.