What’s Vulnerable › Vulnerabilities

CVE-2025-67747: Fickling has missing detection for marshal.loads and types.FunctionType in unsafe modules list

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2025-12-16 · updated 2026-10-07
• Weakness: CWE-184

Description

Fickling is a Python pickling decompiler and static analyzer. Versions prior to 0.1.6 are missing `marshal` and `types` from the block list of unsafe module imports. Fickling started blocking both modules to address this issue. This allows an attacker to craft a malicious pickle file that can bypass fickling since it misses detections for `types.FunctionType` and `marshal.loads`. A user who deserializes such a file, believing it to be safe, would inadvertently execute arbitrary code on their system. This impacts any user or system that uses Fickling to vet pickle files for security issues. The issue was fixed in version 0.1.6.

Affected products

• trailofbits fickling: before 0.1.6 — fixed in 0.1.6

How to fix

Upgrade to a fixed version: trailofbits fickling 0.1.6. Check the vendor advisory for mitigations.

References

• https://github.com/trailofbits/fickling/commit/4e34561301bda1450268d1d7b0b2b151de33b913
• https://github.com/trailofbits/fickling/pull/186
• https://github.com/trailofbits/fickling/releases/tag/v0.1.6
• https://github.com/trailofbits/fickling/security/advisories/GHSA-565g-hwwr-4pp3

Get alerted when CVE-2025-67747 or the next vulnerability affects your stack