Vulnerability · Published Sep 5, 2026 · Assigned by Tcpdump
CVE-2026-31911abort() in libpcap before 1.10.7 on an invalid BPF opcode
Medium 5.5
In plain English
A medium-severity security flaw in libpcap from The Tcpdump Group. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 1% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)5.5Medium
Exploit odds (30 days)0.1%top 98.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.21 | libpcap | 1.10.7-r0 | ALPINE-CVE-2026-31911 |
| Alpine:v3.22 | libpcap | 1.10.7-r0 | ALPINE-CVE-2026-31911 |
| Alpine:v3.23 | libpcap | 1.10.7-r0 | ALPINE-CVE-2026-31911 |
| Alpine:v3.24 | libpcap | 1.10.7-r0 | ALPINE-CVE-2026-31911 |
| Debian:12 | libpcap | no fix listed | DEBIAN-CVE-2026-31911 |
| Debian:13 | libpcap | no fix listed | DEBIAN-CVE-2026-31911 |
| Debian:14 | libpcap | 1.10.7-1 | DEBIAN-CVE-2026-31911 |
| Ubuntu:22.04:LTS | libpcap | no fix listed | UBUNTU-CVE-2026-31911 |
| Ubuntu:24.04:LTS | libpcap | no fix listed | UBUNTU-CVE-2026-31911 |
| Ubuntu:26.04:LTS | libpcap | no fix listed | UBUNTU-CVE-2026-31911 |
| Ubuntu:26.10 | libpcap | no fix listed | UBUNTU-CVE-2026-31911 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| The Tcpdump Group | libpcap | 0 – before 1.10.7 |
Weakness: CWE-617 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H