Vulnerability in The Tcpdump Group Libpcap
CVE-2026-6554
libpcap BPF interpreter treats the offset in the 'ja L' BPF instruction as a signed integer to implement looping via backward jumps, but it does not limit the number of loop iterations. In particular uncommon use cases a crafted filter program can cause the interpreter to loop infinitely.
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
Weakness classification (CWE)
References
- security@tcpdump.org (patch)
Frequently asked questions
- What is CVE-2026-6554?
- CVE-2026-6554 is a medium-severity vulnerability in The Tcpdump Group Libpcap, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 5.5/10. Published 2026-09-05.
- How severe is CVE-2026-6554?
- Medium severity. CVSS v3 base score is 5.5 out of 10.