pyquokka is Vulnerable to Remote Code Execution by Pickle Deserialization via FlightServer

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

9.8 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2025-62515: 0.89% estimated exploitation activity in the next 30 days; percentile 59.41 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Description In the FlightServer class of the pyquokka framework, the doaction() method directly uses pickle.loads() to deserialize action bodies received from Flight clients without any sanitization or validation, which results in a remote code execution vulnerability. The vulnerable code is located in pyquokka/flight.py at line 283, where arbitrary data from Flight clients is directly passed to pickle.loads(). Even more concerning, when FlightServer is configured to listen on 0.0.0.0 (as shown in the provided server example at line 339), this allows attackers across the entire network to perform arbitrary remote code execution by sending malicious pickled payloads through the setconfigs action. In addition, the functions cachegarbagecollect, doput, and doget also contain vulnerability points where pickle.loads is used to deserialize untrusted remote data. Please review and fix these issues accordingly. This report uses the setconfigs action as an example. Proof of Concept Step 1:…

Published by the source

17 Oct 2025, 18:08 UTC

Last modified by the source

29 Jun 2026, 12:26 UTC

Source last checked

26 Oct 2026, 13:35 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-f74j-gffq-vm9p

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-f74j-gffq-vm9p

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# Patch Next advisory brief: CVE-2025-62515

Advisory: pyquokka is Vulnerable to Remote Code Execution by Pickle Deserialization via FlightServer
IDs: CVE-2025-62515, GHSA-f74j-gffq-vm9p
Record: https://patchnext.com/advisories/cve-2025-62515 (revision 2, source checked 26 Oct 2026, 13:35 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI pyquokka: affected <= 0.3.1

## Suggested inspection (read-only)
- `python -m pip show pyquokka`: prints the installed version. Run with the environment that serves production active.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on pyquokka.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-f74j-gffq-vm9p (OSV record GHSA-f74j-gffq-vm9p lists affected ranges: PyPI pyquokka >=0 <=0.3.1)
- Verified: https://github.com/advisories/GHSA-f74j-gffq-vm9p (GitHub-reviewed advisory GHSA-f74j-gffq-vm9p lists affected ranges: PyPI pyquokka >=0 <=0.3.1)

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