CVE-2026-43901
MEDIUMCVE-2026-43901 is a medium-severity (CVSS 6.8) vulnerability in wireshark-mcp. O3 Security confirms whether CVE-2026-43901 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Wireshark MCP: Arbitrary file write via export_objects when WIRESHARK_MCP_ALLOWED_DIRS is not configured
Blast Radius
wireshark-mcpReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Wireshark MCP is an MCP Server that turns tshark into a structured analysis interface, then layers in optional Wireshark suite utilities. In 1.1.5 and earlier, wireshark-mcp exposes a wireshark_export_objects MCP tool that accepts an attacker-controlled dest_dir parameter and passes it to tshark's --export-objects flag with no mandatory path restriction. The path sandbox (_allowed_dirs) is None by default and only activates when the environment variable WIRESHARK_MCP_ALLOWED_DIRS is explicitly set. In a default installation, any directory on the filesystem can be used as the export destination.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | wireshark-mcp | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for wireshark-mcp. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of wireshark-mcp has shipped for CVE-2026-43901 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-43901 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-43901. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-43901 in your dependencies?
O3 detects CVE-2026-43901 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.