# CVE-2026-56304: picklescan unsafe deserialization in logging.FileHandler

Source: https://junglewise.ai/threats/cve-2026-56304-picklescan-unsafe-deserialization-in-logging-filehandler  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-20. Updated: 2026-06-21  
License: CC BY 4.0 with a link back

CVE-2026-56304 · Severity: medium · CVSS 6.5 · Published 2026-06-20

picklescan is a tool used to scan Python pickle files for malicious code. A vulnerability in versions before 1.0.1 allows an attacker to create empty files anywhere on the system's storage. While this cannot be used to steal data, it can be used to disrupt operations by creating 'lock' files that prevent the application from starting or functioning correctly.

Technologies: [picklescan (PyPI)](https://junglewise.ai/threats/technologies/picklescan). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2026-56304 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-56304 being exploited in the wild.

**How severe is CVE-2026-56304?** Medium severity, with a CVSS score of 6.5, published 20 June 2026.

**Which products and versions are affected?** picklescan (PyPI) ECOSYSTEM:introduced=0,fixed=1.0.1.

**Is there a fix for CVE-2026-56304?** Yes. picklescan (PyPI): upgrade to 1.0.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-56304 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-56304?** Check whether you run picklescan (PyPI) at an affected version. 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.

## How to fix

- picklescan (PyPI): upgrade to 1.0.1 or later

  ```sh
  pip install "picklescan>=1.0.1"
  ```


## Technical details

A deserialization vulnerability (CWE-502) exists in picklescan due to the unsafe processing of untrusted pickle data. By crafting a malicious payload that instantiates the 'logging.FileHandler' class, an attacker can bypass typical Remote Code Execution (RCE) blocklists. This exploit primitive allows for the creation of zero-byte files in arbitrary locations where the application has write permissions. While it does not allow for overwriting existing data, it can be used for filesystem pollution or to trigger a Denial of Service (DoS) by creating specific lock files that alter application logic. The issue is fixed in version 1.0.1.

## Affected products

- mmaitre314 picklescan < 1.0.1

## Identifiers

- CVE-2026-56304
- GHSA-m7j5-r2p5-c39r
- PYSEC-2026-225

## Timeline

- 2026-02-02: advisory: GitHub Security Advisory published
- 2026-06-20: disclosed: CVE-2026-56304 published to NVD

## References

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

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