Process hang via unbounded BPF backward jumps
Published Sep 5, 2026 · Updated Sep 8, 2026
Infinite-loop denial of service in The Tcpdump Group libpcap before 1.10.7 allows local users to hang a consuming process. The pcapint_filter_with_aux_data() BPF interpreter sign-extends the ja L offset for backward jumps but places no limit on repeated traversal of the same instructions. Exploitation requires an application to pass an externally supplied compiled filter program to pcap_offline_filter() or bpf_filter() without first validating it.
Summary
What happened
Infinite-loop denial of service in The Tcpdump Group libpcap before 1.10.7 allows local users to hang a consuming process. The pcapint_filter_with_aux_data() BPF interpreter sign-extends the ja L offset for backward jumps but places no limit on repeated traversal of the same instructions. Exploitation requires an application to pass an externally supplied compiled filter program to pcap_offline_filter() or bpf_filter() without first validating it.
The record
- CVE
- CVE-2026-6554
- Published
- Sep 5, 2026
- Updated
- Sep 8, 2026
- Vendor
- The Tcpdump Group
- Product
- libpcap
- Classifications
- CWE-835, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 5, 2026CVE publishedPublication date reported by the CVE source.
- Sep 8, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <1.10.7
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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