CVE-2026-6244 division by zero in libpcap before 1.10.7
A crafted BPF filter program can cause a division by zero in libpcap, leading to a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-6244?
CVE-2026-6244 is a medium-severity denial of service vulnerability in The Tcpdump Group libpcap, published on 5 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
libpcap BPF interpreter for the 'div #k' and 'mod #k' ALU instructions does not check whether the immediate value is zero. In particular uncommon use cases a crafted filter program can cause a division by zero.
Weakness: CWE-369
Which versions are affected by CVE-2026-6244?
How do I fix CVE-2026-6244?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-6244 being exploited?
There is no known exploitation of CVE-2026-6244 in the wild and no public exploit code.
Sources
Also known as ALPINE-CVE-2026-6244, AZL-99738, AZL-99936, BELL-CVE-2026-6244, DEBIAN-CVE-2026-6244, ECHO-84b0-6123-3737 and 2 more.