# CVE-2025-71376: picklescan detection bypass via idlelib fetch_completions

Source: https://junglewise.ai/threats/cve-2025-71376-picklescan-detection-bypass-via-idlelib-fetch-completions  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-23. Updated: 2026-06-23  
License: CC BY 4.0 with a link back

CVE-2025-71376 · Severity: high · CVSS 8.1 · Published 2026-06-23

picklescan is a security tool used to scan Python pickle files and machine learning models for malicious code. A vulnerability in versions prior to 0.0.29 allows specially crafted malicious files to bypass detection by using a specific Python internal function. If a user trusts the scan results and opens the file, an attacker could execute arbitrary commands on the user's system, potentially leading to a full system compromise or data theft.

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

## Quick answers

**Is CVE-2025-71376 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-71376 being exploited in the wild.

**How severe is CVE-2025-71376?** High severity, with a CVSS score of 8.1, published 23 June 2026.

**Which products and versions are affected?** picklescan (PyPI) < 0.0.29, ECOSYSTEM:introduced=0,fixed=0.0.29.

**Is there a fix for CVE-2025-71376?** Yes. picklescan (PyPI): upgrade to 0.0.29 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2025-71376 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2025-71376?** 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 0.0.29 or later

  ```sh
  pip install "picklescan>=0.0.29"
  ```


## Technical details

A deserialization bypass exists in picklescan before version 0.0.29. The scanner's logic fails to identify the 'idlelib.autocomplete.AutoComplete.fetch_completions' function as dangerous when used within a pickle's __reduce__ method. An attacker can craft a malicious pickle file that, when scanned, appears safe but executes arbitrary system commands via the 'os.system' or similar calls when subsequently loaded using 'pickle.load()'. This vulnerability is categorized as CWE-502 (Deserialization of Untrusted Data). Users are advised to upgrade to version 0.0.29 or later to ensure these payloads are correctly flagged.

## Affected products

- mmaitre314 picklescan < 0.0.29

## Identifiers

- CVE-2025-71376
- GHSA-7cq8-mj8x-j263
- PYSEC-2026-4133

## Timeline

- 2025-08-26: advisory: GitHub Security Advisory GHSA-7cq8-mj8x-j263 published
- 2026-06-23: disclosed: CVE-2025-71376 published to NVD

## References

- [https://github.com/mmaitre314/picklescan/security/advisories/GHSA-7cq8-mj8x-j263](https://github.com/mmaitre314/picklescan/security/advisories/GHSA-7cq8-mj8x-j263)
- [https://www.vulncheck.com/advisories/picklescan-arbitrary-code-execution-via-undetected-idlelib-autocomplete-autocomplete-fetch-completions](https://www.vulncheck.com/advisories/picklescan-arbitrary-code-execution-via-undetected-idlelib-autocomplete-autocomplete-fetch-completions)

## Related threats

- [picklescan detection bypass via _operator.methodcaller](https://junglewise.ai/threats/cve-2025-71375-picklescan-detection-bypass-via-operator-methodcaller)
- [picklescan security bypass via operator.methodcaller](https://junglewise.ai/threats/cve-2025-71373-picklescan-security-bypass-via-operator-methodcaller)
- [Picklescan detection bypass via numpy getlincoef gadget](https://junglewise.ai/threats/cve-2025-71372-picklescan-detection-bypass-via-numpy-getlincoef-gadget)
- [picklescan safety check bypass via PyTorch decoder basichandlers](https://junglewise.ai/threats/cve-2025-71369-picklescan-safety-check-bypass-via-pytorch-decoder-basichandlers)
- [picklescan security bypass via _operator.attrgetter function call](https://junglewise.ai/threats/cve-2025-71367-picklescan-security-bypass-via-operator-attrgetter-function-call)