CVE-2026-31912 OOBR in libpcap before 1.10.7
A crafted BPF filter program in libpcap can cause out-of-bounds memory reads, potentially leading to information disclosure or 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-2026-31912?
CVE-2026-31912 is a medium-severity memory corruption 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 detects neither reaching the end of the filter program buffer due to lack of a return instruction nor executing a jump instruction with an offset that translates to a pointer outside of the buffer. In particular uncommon use cases a crafted filter program can cause the interpreter to try reading the OS process memory in the 32GiB around the buffer on 64-bit architectures and in the entire address space on 32-bit architectures.
Which versions are affected by CVE-2026-31912?
How do I fix CVE-2026-31912?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-31912 being exploited?
There is no known exploitation of CVE-2026-31912 in the wild and no public exploit code.
Sources
Also known as ALPINE-CVE-2026-31912, AZL-99741, AZL-99921, BELL-CVE-2026-31912, DEBIAN-CVE-2026-31912, ECHO-c577-82f0-747c and 2 more.