CVE-2025-62703
HIGHFugue is Vulnerable to Remote Code Execution by Pickle Deserialization via FlaskRPCServer
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
fugueReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | fugue | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for fugue. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of fugue has shipped for CVE-2025-62703 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2025-62703 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2025-62703. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-62703 in your dependencies?
O3 detects CVE-2025-62703 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.