CVE-2025-71321 picklescan - Arbitrary File Writing via distutils Module Bypass
Attackers can bypass blocklists in picklescan to write arbitrary files via distutils, leading to remote code execution or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-71321?
CVE-2025-71321 is a critical unsafe deserialization vulnerability in picklescan, published on 17 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-502
Which versions are affected by CVE-2025-71321?
3 open source packages ship an affected version, including picklescan.
| Package | Affected | Fixed in |
|---|---|---|
picklescan PyPI | All versions | 0.0.33 |
picklescan PyPI | All versions | 0.0.33 |
picklescan PyPI | All versions | 0.0.33 |
How do I fix CVE-2025-71321?
Upgrade picklescan to 0.0.33 or later.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2025-71321 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-71321 exists.
Sources
Also known as GHSA-m273-6v24-x4m4, PYSEC-2026-1791.