Summary
PyO3 has type confusion when accessing data from sublasses of subclasses of native types with abi3 feature
PyO3 0.28.1 added support for #[pyclass(extends=PyList)] struct NativeSub (and other native types) when targeting Python 3.12 and up with the abi3 feature.
It was discovered that subclasses of such classes would use the type of the subclass when attempting to access to data of NativeSub contained within Python objects, amounting to memory corruption.
PyO3 0.28.2 fixed the issue by using the type of (e.g.) NativeSub correctly.
Impact
An object is accessed using a type that is incompatible with its actual type, causing the runtime to interpret memory incorrectly. Typical impact: memory safety violations, unexpected behavior, or code execution.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is GHSA-47QC-857F-7W7F? GHSA-47QC-857F-7W7F is a high-severity type confusion vulnerability in pyo3 (rust), affecting versions >= 0.28.0, < 0.28.2. It is fixed in 0.28.2. An object is accessed using a type that is incompatible with its actual type, causing the runtime to interpret memory incorrectly.
- Which versions of pyo3 are affected by GHSA-47QC-857F-7W7F? pyo3 (rust) versions >= 0.28.0, < 0.28.2 is affected.
- Is there a fix for GHSA-47QC-857F-7W7F? Yes. GHSA-47QC-857F-7W7F is fixed in 0.28.2. Upgrade to this version or later.
- Is GHSA-47QC-857F-7W7F exploitable, and should I be worried? Whether GHSA-47QC-857F-7W7F is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-47QC-857F-7W7F is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-47QC-857F-7W7F? Upgrade
pyo3to 0.28.2 or later.