Vulnerability in The Tcpdump Group libpcap

[ Description ]Official description

In BPF instructions that load/store a value from/to a scratch memory register the register index is an unsigned 32-bit integer and must not exceed 15, but libpcap BPF interpreter does not validate the value. In particular uncommon use cases a crafted filter program can cause the interpreter to try reading and writing the OS process memory in the 16GiB starting at the current stack frame on 64-bit architectures and in the entire address space on 32-bit architectures.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund30 Sep 2026WID-SEC-2026-3691

  Red Hat Enterprise Linux (libpcap): Vulnerability allows information disclosure and code execution Translated from German

  CVE-2026-0799

[ References ]References

• github.com/the-tcpdump-group/libpcap/commit/48e8960a7108e9e828f9d7bdc7e97bdab841aec7patch