Deserialization of Untrusted Data Affecting ply package, versions [0,]
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.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applicationsSnyk Learn
Learn about Deserialization of Untrusted Data vulnerabilities in an interactive lesson.
Start learning- Snyk IDSNYK-PYTHON-PLY-15046763
- published21 Jan 2026
- disclosed20 Jan 2026
- creditbohmiiidd
Introduced: 20 Jan 2026
CVE-2025-56005 (opens in a new tab)How to fix?
There is no fixed version for ply.
Overview
ply is a Python Lex & Yacc
Affected versions of this package are vulnerable to Deserialization of Untrusted Data via the picklefile parameter in the yacc function. An attacker can execute arbitrary code by supplying a specially crafted pickle file that is deserialized without validation.
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.