CVE-2025-62703: fugue · Deserialization of Untrusted Data
Affects fugueSource CVE Database V5
Not known to be exploited · CVSS 8.8 High.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.7% chance of exploitation in 30 days – higher than 55% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Nov 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
PyPIfuguepkg:pypi/fugueOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
To mitigate CVE-2025-62703, European organizations should immediately upgrade Fugue to a version later than 0.9.2 where the vulnerability is patched. If upgrading is not immediately feasible, organizations should restrict network access to the Fugue RPC server by implementing strict firewall rules and network segmentation to limit exposure to trusted internal clients only. Employing VPNs or zero-trust network architectures can further reduce attack surfaces. Monitoring and logging RPC server activity for unusual or unexpected serialized payloads can help detect exploitation attempts. Security teams should audit their distributed computing environments to identify any Fugue deployments and verify patch levels. Additionally, consider disabling or restricting RPC server functionality if not required. Educate developers and administrators about the risks of unsafe deserialization and promote secure coding practices, such as avoiding deserialization of untrusted data or using safer serialization formats. Regular vulnerability scanning and penetration testing targeting RPC interfaces can help identify residual risks. Finally, maintain incident response plans to quickly contain and remediate any compromise stemming from this vulnerability.
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.