What is 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.
The record classifies CVE-2026-6554 under weakness class CWE-835. Its CVSS v3 base vector states that the flaw requires local access to the host, needs low-privilege credentials, needs no user interaction, and has high impact on availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 30 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 5.5 — MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - EPSS (FIRST)
- 0.0% probability of exploitation in the next 30 days, higher than 85.3% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 6.2/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-09-05
Is CVE-2026-6554 being exploited?
It currently carries a trending score of 51 in the Threadlinqs vulnerability feed.
Affected products and versions
- The Tcpdump Group: libpcap
How to fix CVE-2026-6554
No vendor patch reference has been recorded for CVE-2026-6554 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-6554
No threat campaign in the Threadlinqs corpus currently references CVE-2026-6554, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.
Sources
Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.