5.5

CVE-2026-31911: the tcpdump group libpcap Reachable Assertion

CVSS: 5.5v3.1MediumAwaiting analysis
AliasesALPINE-CVE-2026-31911UBUNTU-CVE-2026-31911DEBIAN-CVE-2026-31911
Published 05-09-2026Last modified 08-09-2026
Open JSON

Vulnerability summary

CVE-2026-31911 is a medium (CVSS 5.5) Reachable Assertion vulnerability in the tcpdump group libpcap. EPSS estimates a 0.10% chance of exploitation in the next 30 days, higher than 1% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.10%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 11 · Related 10
MGASA-2026-0416OPENSUSE-SU-2026:11744-1OPENSUSE-SU-2026:21940-1SUSE-SU-2026:23737-1SUSE-SU-2026:23829-1SUSE-SU-2026:23892-1

Timeline

  1. 05-09-2026
    PublishedVulnerability first disclosed.
  2. 08-09-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.10%

Chance of exploitation in the next 30 days

Percentile

1%

Versus all other CVEs

30-day change

+0.01 pp

From 0.10% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.10%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Alpine1 product
  • libpcap< 1.10.7-r0
Debian1 product
  • libpcapAll versions (No fix recorded) | < 1.10.7-1
The tcpdump group1 product
Ubuntu1 product
  • libpcapAll versions (No fix recorded)

4 vendors · 4 products

References

6 links