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

What is CVE-2026-56304?

CVE-2026-56304 is a medium-severity unsafe deserialization vulnerability in picklescan, published on 20 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-502

Which versions are affected by CVE-2026-56304?

3 open source packages ship an affected version, including picklescan. It affects 1 product.

Products include Mmaitre314 Picklescan.

How do I fix CVE-2026-56304?

Upgrade picklescan to 1.0.1 or later.

Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.

Is CVE-2026-56304 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-56304 exists.

Other vulnerabilities in picklescan

• CVE-2025-10155 PickleScan Security Bypass Using Misleading File Extension Critical 9.3
• CVE-2025-10156 PickleScan Security Bypass via Bad CRC in ZIP Archive Critical 9.3
• CVE-2025-10157 PickleScan Bypasses Unsafe Globals Check Using Submodule Imports Critical 9.3
• CVE-2025-71348 picklescan - Arbitrary Code Execution via torch.utils._config_module.load_config Bypass High 7.6
• CVE-2025-71357 picklescan - Arbitrary Code Execution via Undetected idlelib.pyshell.ModifiedInterpreter.runcommand High 7.6

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• GitHub advisory
• How this page is made

Also known as GHSA-hqgf-f82p-fjh7, GHSA-m7j5-r2p5-c39r, PYSEC-2026-225.