Code execution via incomplete unsafe-import denylist
Published Jan 10, 2026 · Updated Jan 10, 2026
Static-analysis bypass in Trail of Bits Fickling before 0.1.7 allows attackers to evade unsafe-pickle checks via crafted imports. The unsafe_imports() method compares module names with an incomplete hardcoded denylist that omits ctypes, importlib, runpy, code, and multiprocessing. Code execution requires a downstream user or system to trust the likely-safe result and load the malicious pickle, which runs code with the loading process's privileges.
Summary
What happened
Static-analysis bypass in Trail of Bits Fickling before 0.1.7 allows attackers to evade unsafe-pickle checks via crafted imports. The unsafe_imports() method compares module names with an incomplete hardcoded denylist that omits ctypes, importlib, runpy, code, and multiprocessing. Code execution requires a downstream user or system to trust the likely-safe result and load the malicious pickle, which runs code with the loading process's privileges.
The record
- CVE
- CVE-2026-22609
- Published
- Jan 10, 2026
- Updated
- Jan 10, 2026
- Vendor
- Trail of Bits
- Product
- Fickling
- Classifications
- CWE-502, CWE-184, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 10, 2026CVE publishedPublication date reported by the CVE source.
- Jan 10, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 0.1.7
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- ctypes unsafe_imports bypass proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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