CVE-2026-6554: CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop') in The Tcpdump Group libpcap
Description
CVE-2026-6554 is a medium severity vulnerability in the libpcap library used by The Tcpdump Group. The issue arises from the BPF interpreter treating the offset in the 'ja L' instruction as a signed integer to implement loops without limiting the number of iterations. This can cause an infinite loop when processing crafted filter programs. The vulnerability affects libpcap versions from 0 up to but not including 1.10.7. There is no explicit patch information provided in the input data.
CVSS v3.1
Score 5.5medium
Affected software
The Tcpdump Group
libpcap
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The libpcap BPF interpreter uses the offset in the 'ja L' BPF instruction as a signed integer to implement backward jumps for looping. However, it does not impose any limit on the number of loop iterations, which can lead to an infinite loop in uncommon use cases when a crafted filter program is processed. This infinite loop can cause a denial of service by making the interpreter hang indefinitely. The vulnerability is identified as CWE-835 (Loop with Unreachable Exit Condition).
Potential Impact
The vulnerability can cause a denial of service (DoS) condition by triggering an infinite loop in the BPF interpreter of libpcap. This results in high availability impact (A:H) but does not affect confidentiality or integrity. The attack vector requires local access with low privileges and no user interaction is needed.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since no patch or official fix information is provided, users should monitor for updates from The Tcpdump Group. Until a fix is available, avoid using untrusted or crafted filter programs that could trigger this infinite loop.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Tcpdump
- Date Reserved
- 2026-04-17T22:00:24.313Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a9c688aacd9273b49460ec2
Added to database: 09/05/2026, 19:07:54 UTC
Last enriched: 09/15/2026, 01:02:16 UTC
Last updated: 10/20/2026, 18:48:23 UTC
Views: 96
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