Quick answers
- Is CVE-2026-6244 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-6244 being exploited in the wild.
- How severe is CVE-2026-6244?
- Medium severity, with a CVSS score of 5.5, published 5 September 2026.
- Which products and versions are affected?
- The Tcpdump Group libpcap <UNKNOWN>.
- Is there a fix for CVE-2026-6244?
- A patch was published on 2026-09-05: Patch available via commit 98bb921 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-6244 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-6244?
- Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability exists in the BPF interpreter's handling of 'div #k' and 'mod #k' ALU (arithmetic/logic unit) instructions, where k is an immediate constant value. While the interpreter correctly validates that the X register is non-zero for 'div x' and 'mod x' operations, it assumes k is never zero for immediate-value instructions. However, external filter programs passed via pcap_offline_filter() or bpf_filter() may not have been validated by libpcap, allowing an attacker to supply a crafted filter containing division or modulo by zero. Exploitation requires network reachability or the ability to supply a malicious filter program; when executed, this causes a SIGFPE signal that terminates the process. The fix treats 'div #k' and 'mod #k' the same as variable-operand instructions by explicitly checking for zero before division.
Affected products
- The Tcpdump Group libpcap <UNKNOWN>
Timeline
- 2026-09-05: disclosed
- 2026-09-05: patched: Patch available via commit 98bb921