# CVE-2025-71321: picklescan - Arbitrary File Writing via distutils Module Bypass

Status: published. Published: 2026-06-17. Updated: 2026-11-08.

picklescan before 0.0.33 contains an arbitrary file writing vulnerability that allows attackers to bypass the dangerous blocklist by using distutils.file_util.write_file. Attackers can construct malicious pickle objects to overwrite critical system files and achieve denial of service or remote code execution.

## Remediation

- fix: picklescan (PyPI): OSV reports a fixed version 0.0.33. Check the advisory for supported release branches. (source: OSV GHSA-m273-6v24-x4m4) — https://github.com/advisories/GHSA-m273-6v24-x4m4

## Affected products and versions

- picklescan / picklescan (picklescan): ≥ 0; < 0.0.33 (affected, semver); 0.0.33 (unaffected, semver). Source: CNA: VulnCheck
-  / picklescan (picklescan): 0.0.1 (affected, PyPI); 0.0.10 (affected, PyPI); 0.0.11 (affected, PyPI); 0.0.12 (affected, PyPI); 0.0.13 (affected, PyPI); 0.0.14 (affected, PyPI); 0.0.15 (affected, PyPI); 0.0.16 (affected, PyPI); 0.0.17 (affected, PyPI); 0.0.18 (affected, PyPI); 0.0.19 (affected, PyPI); 0.0.2 (affected, PyPI); 0.0.20 (affected, PyPI); 0.0.21 (affected, PyPI); 0.0.22 (affected, PyPI); 0.0.23 (affected, PyPI); 0.0.24 (affected, PyPI); 0.0.25 (affected, PyPI); 0.0.26 (affected, PyPI); 0.0.27 (affected, PyPI); 0.0.28 (affected, PyPI); 0.0.29 (affected, PyPI); 0.0.3 (affected, PyPI); 0.0.30 (affected, PyPI); 0.0.31 (affected, PyPI); 0.0.32 (affected, PyPI); 0.0.4 (affected, PyPI); 0.0.5 (affected, PyPI); 0.0.6 (affected, PyPI); 0.0.7 (affected, PyPI); 0.0.8 (affected, PyPI); 0.0.9 (affected, PyPI); Ecosystem version events: introduced 0; fixed 0.0.33. Source: OSV GHSA-m273-6v24-x4m4

## Severity and prioritization

- CVSS 4.0: 9.3 (critical); CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 9.8 (critical); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: 0.82% as of 2026-11-08; percentile 57.61%

- SSVC: exploitation poc; automatable yes; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-502

## Exploit evidence

- exploit: https://github.com/mmaitre314/picklescan/security/advisories/GHSA-m273-6v24-x4m4 (ADP: CISA-ADP)

## References

- https://github.com/mmaitre314/picklescan/security/advisories/GHSA-m273-6v24-x4m4 (CNA: VulnCheck; vendor-advisory)

- https://www.vulncheck.com/advisories/picklescan-arbitrary-file-writing-via-distutils-module-bypass (CNA: VulnCheck; third-party-advisory)

- https://github.com/mmaitre314/picklescan/security/advisories/GHSA-m273-6v24-x4m4 (ADP: CISA-ADP; exploit)

- https://github.com/advisories/GHSA-m273-6v24-x4m4 (OSV / GitHub Security Advisories; advisory)

- https://osv.dev/vulnerability/GHSA-m273-6v24-x4m4 (OSV / GitHub Security Advisories; osv)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2025-71321; retrieved 2026-11-08; source updated 2026-11-08

- OSV / GitHub Security Advisories: https://osv.dev/vulnerability/GHSA-m273-6v24-x4m4; retrieved 2026-11-08; source updated 2026-07-07

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2025-71321; retrieved 2026-11-08; source updated Not reported

Revision: 142a0e7d97af892ba999294aaa845eca87caef7b76456e9154070380411d0752

Canonical: https://y2.dev/cve/CVE-2025-71321

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