Detection bypass via suppressed builtins import nodes
Published Jan 10, 2026 · Updated Jan 10, 2026
Detection bypass in Fickling before 0.1.7 allows remote attackers to make malicious pickle files appear likely safe. The pickle-to-AST interpreter in fickling/fickle.py suppresses import nodes for builtin, builtins, and builtins, so unsafe-import analysis misses calls such as import and getattr. Exploitation requires a consumer to trust Fickling's verdict and deserialize the crafted file, which then executes attacker-selected commands in that consumer's context.
Summary
What happened
Detection bypass in Fickling before 0.1.7 allows remote attackers to make malicious pickle files appear likely safe. The pickle-to-AST interpreter in fickling/fickle.py suppresses import nodes for builtin, builtins, and builtins, so unsafe-import analysis misses calls such as import and getattr. Exploitation requires a consumer to trust Fickling's verdict and deserialize the crafted file, which then executes attacker-selected commands in that consumer's context.
The record
- CVE
- CVE-2026-22612
- Published
- Jan 10, 2026
- Updated
- Jan 10, 2026
- Vendor
- Trail of Bits
- Product
- Fickling
- Classifications
- CWE-502, T1204.002
- 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
- Builtins-blindness malicious pickle proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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