PYSEC-2026-491
Apache Pyfory python is vulnerable to deserialization of untrusted data
Details
Deserialization of untrusted data in python in pyfory versions 0.12.0 through 0.12.2, or the legacy pyfury versions from 0.1.0 through 0.10.3: allows arbitrary code execution. An application is vulnerable if it reads pyfory serialized data from untrusted sources. An attacker can craft a data stream that selects pickle-fallback serializer during deserialization, leading to the execution of `pickle.loads`, which is vulnerable to remote code execution.
Users are recommended to upgrade to pyfory version 0.12.3 or later, which has removed pickle fallback serializer and thus fixes this issue.
Are you affected?
Enter the version of the package you're using.
Affected packages
0.1.0 No fixed version published yet for pyfury (pip). Pin to a known-safe version or switch to an alternative.
References
- https://nvd.nist.gov/vuln/detail/CVE-2025-61622 [ADVISORY]
- https://github.com/apache/fory/pull/2629 [WEB]
- https://github.com/apache/fory/commit/379b948ecae5c3b849e5bdb3997978c9a163e40b [WEB]
- https://github.com/apache/fory [PACKAGE]
- https://github.com/apache/fory/releases/tag/v0.12.3 [WEB]
- https://lists.apache.org/thread/vfn9hp9qt06db5yo1gmj3l114o3o2csd [WEB]
- http://www.openwall.com/lists/oss-security/2025/09/29/3 [WEB]
- https://pypi.org/project/pyfury [PACKAGE]
- https://github.com/advisories/GHSA-538v-3wq9-4h3r [ADVISORY]