Deserialization of Untrusted Data Affecting fickling package, versions [,0.1.7)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-PYTHON-FICKLING-14912437
- published13 Jan 2026
- disclosed9 Jan 2026
- creditApollyon
Introduced: 9 Jan 2026
CVE-2026-22612 (opens in a new tab)How to fix?
Upgrade fickling to version 0.1.7 or higher.
Overview
fickling is an A static analyzer and interpreter for Python pickle data
Affected versions of this package are vulnerable to Deserialization of Untrusted Data in the analysis of pickle files, where import nodes for certain modules such as builtins are not emitted in the abstract syntax tree, resulting in the security analysis being unable to detect dangerous imports. An attacker can execute arbitrary code by including dangerous functions from builtins, such as __import__, which will be executed when the malicious file is loaded under the assumption that it is safe because it is tagged LIKELY_SAFE.
Details
Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating object from sequence of bytes is called deserialization. Serialization is commonly used for communication (sharing objects between multiple hosts) and persistence (store the object state in a file or a database). It is an integral part of popular protocols like Remote Method Invocation (RMI), Java Management Extension (JMX), Java Messaging System (JMS), Action Message Format (AMF), Java Server Faces (JSF) ViewState, etc.
Deserialization of untrusted data (CWE-502) is when the application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, thus allowing the attacker to control the state or the flow of the execution.