fugue-project fugue up to 0.9.2 fugue/rpc/flask.py _decode deserialization

Summaryinfo

A vulnerability classified as very critical has been found in fugue-project fugue up to 0.9.2. This issue affects the function _decode of the file fugue/rpc/flask.py. This manipulation causes deserialization. This vulnerability is registered as CVE-2025-62703. The attack requires access to the local network. No exploit is available. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability has been found in fugue-project fugue up to 0.9.2 and classified as very critical. Affected by this vulnerability is the function _decode of the file fugue/rpc/flask.py. The manipulation with an unknown input leads to a deserialization vulnerability. The CWE definition for the vulnerability is CWE-502. The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Fugue is a unified interface for distributed computing that lets users execute Python, Pandas, and SQL code on Spark, Dask, and Ray with minimal rewrites. In version 0.9.2 and prior, there is a remote code execution vulnerability by pickle deserialization via FlaskRPCServer. The Fugue framework implements an RPC server system for distributed computing operations. In the core functionality of the RPC server implementation, I found that the _decode() function in fugue/rpc/flask.py directly uses cloudpickle.loads() to deserialize data without any sanitization. This creates a remote code execution vulnerability when malicious pickle data is processed by the RPC server. The vulnerability exists in the RPC communication mechanism where the client can send arbitrary serialized Python objects that will be deserialized on the server side, allowing attackers to execute arbitrary code on the victim's machine. This issue has been patched via commit 6f25326.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2025-62703 since 10/20/2025. The exploitation appears to be easy. Access to the local network is required for this attack to succeed. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/27/2025).

Applying the patch 6f25326779fd1f528198098d6287c5a863176fc0 is able to eliminate this problem. The bugfix is ready for download at github.com.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2025-199646). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Project Management Software

Vendor

• fugue-project

Name

• fugue

Version

• 0.9.0
• 0.9.1
• 0.9.2

License

• open-source

Website

• Product: https://github.com/fugue-project/fugue/

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Be aware that VulDB is the high quality source for vulnerability data.

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