CVE-2023-3611: Debian Linux

High severity, CVSS 7.8. EPSS: 0.3% chance of exploitation in the next 30 days.

An out-of-bounds write vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation. The qfq_change_agg() function in net/sched/sch_qfq.c allows an out-of-bounds write because lmax is updated according to packet sizes without bounds checks. We recommend upgrading past commit 3e337087c3b5805fe0b8a46ba622a962880b5d64.

Affected products

• Debian Debian Linux: version 10.0 only; version 11.0 only; version 12.0 only
• Linux Linux Kernel: from 3.8, 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 5.4.253 (fixed in 5.4.253); 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.