Arbitrary code execution via unsafe model deserialization
Published Feb 26, 2026 · Updated Feb 26, 2026
Unsafe deserialization in Flair 0.4.1 through 0.15.1 allows local users to execute arbitrary code by loading a malicious language model. LanguageModel.load_language_model passes the model file to torch.load with weights_only=False, enabling pickle object reconstruction and code execution. Exploitation requires control of a model file path consumed by the loading process, and the code runs with that process's privileges.
Summary
What happened
Unsafe deserialization in Flair 0.4.1 through 0.15.1 allows local users to execute arbitrary code by loading a malicious language model. LanguageModel.load_language_model passes the model file to torch.load with weights_only=False, enabling pickle object reconstruction and code execution. Exploitation requires control of a model file path consumed by the loading process, and the code runs with that process's privileges.
The record
- CVE
- CVE-2026-3071
- Published
- Feb 26, 2026
- Updated
- Feb 26, 2026
- Vendor
- flairNLP
- Product
- Flair
- Classifications
- CWE-502, T1203
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 26, 2026CVE publishedPublication date reported by the CVE source.
- Feb 26, 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=0.4.1 <=*
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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
- HiddenLayer malicious Flair model proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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