What is CVE-2026-31911?

CVE-2026-31911 is a medium-severity vulnerability in The Tcpdump Group Libpcap, classified under Reachable Assertion. CVSS score: 5.5/10. Published 2026-09-05.

How severe is CVE-2026-31911?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Vulnerability in The Tcpdump Group Libpcap

CVE-2026-31911

libpcap BPF interpreter calls abort() if it encounters a BPF instruction that has an invalid opcode. In particular uncommon use cases a crafted filter program can terminate the OS process.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Affected products

The Tcpdump Group Libpcap

Weakness classification (CWE)

CWE-617 — Reachable Assertion

References

security@tcpdump.org (patch)

Frequently asked questions

What is CVE-2026-31911?: CVE-2026-31911 is a medium-severity vulnerability in The Tcpdump Group Libpcap, classified under Reachable Assertion. CVSS score: 5.5/10. Published 2026-09-05.
How severe is CVE-2026-31911?: Medium severity. CVSS v3 base score is 5.5 out of 10.