CVE-2026-5536
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA weakness has been identified in FedML-AI FedML up to 0.8.9. Affected is the function sendMessage of the file grpc_server.py of the component gRPC server. Executing a manipulation can lead to deserialization. The attack may be performed from remote. The vendor was contacted early about this disclosure but did not respond in any way.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceA deserialization vulnerability exists in FedML-AI FedML up to version 0.8.9 in the sendMessage function of the gRPC server component (grpc_server.py). The vulnerability allows remote attackers to manipulate data leading to unsafe deserialization, which could result in code execution or other attacks.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data<= 0.8.9CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify FedML installation and versionRun 'pip show fedml' or check your Python environment for the installed fedml package versionAffected if The installed version is 0.8.9 or lower
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Locate grpc_server.py in your FedML installationSearch the FedML package directory for grpc_server.py using 'find /path/to/fedml -name grpc_server.py' or equivalentAffected if The file exists and contains a sendMessage function that handles deserialized data
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Examine how sendMessage processes incoming dataInspect the grpc_server.py source code and look for pickle.loads, yaml.load, or similar unsafe deserialization calls within the sendMessage functionAffected if The function uses pickle, yaml without SafeLoader, or other unsafe deserialization mechanisms
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Determine if the gRPC server is exposed to networkCheck your deployment configuration for any running FedML gRPC server instances and their binding addressesAffected if The gRPC server is listening on a network-accessible interface
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Verify if FedML gRPC service is enabled in your environmentReview your FedML startup scripts or service configuration to confirm the gRPC server component is runningAffected if The gRPC server is actively running and accepting connections
You are affected if FedML version 0.8.9 or lower is installed, the gRPC server is running with the vulnerable sendMessage function using unsafe deserialization, and the server is network-accessible.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUntil the vendor releases a patch, mitigate by network isolating the gRPC server, implementing strict input validation on all gRPC messages before deserialization, and considering migration to safer serialization formats (e.g., Protocol Buffers with strict schema validation).
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-5536 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-5536 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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