CVE-2024-27758 is a high-severity (CVSS 8.4) Missing Authentication vulnerability in rpyc. A fix is available for rpyc — see the affected versions and patch details below.
RPyC's missing security check results in code execution when using numpy.array on the server-side.
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-27758.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
rpycReal-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
An issue in Open Source: RPyC v.4.00 thru v.5.3.1 allows a remote attacker to execute arbitrary code via a crafted script to the __array__ attribute component. This vulnerability was introduced in 9f45f826.
Attack Vector
RPyC services that rely on the __array__ attribute used by numpy are impacted. When the server-side exposes a method that calls the attribute named __array__ for a a client provided netref (e.g., np.array(client_netref)), a remote attacker can craft a class which results in remote code execution
Impact
Assuming the system exposes a method that calls the attribute __array__, an attacker can execute code using the vulnerable component.
Patches
The fix is available in RPyC 6.0.0. The major version change is because some users may need to set allow_pickle to True when migrating to RPyC 6.
Workarounds
While the recommend fix is to upgrade to RPyC 6.0.0, the workaround is to apply bba1d356 as patch.
Affected Component
The affected component is the __array__ method constructed for NetrefClass.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | rpyc | ≥ 4.0.0&&< 6.0.0 | 6.0.0pip install --upgrade 'rpyc==6.0.0' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rpyc, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update rpyc to 6.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-27758 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
Frequently Asked Questions
Is CVE-2024-27758 in your dependencies?
Find it across PyPI, including transitive dependencies.