CVE-2026-41586 — hyperledger-fabric-orderer
CVE-2026-41586 is a Deserialization of Untrusted Data vulnerability in hyperledger-fabric-orderer. A fix is available for hyperledger-fabric-orderer — see the affected versions and patch details below.
ObjectInputStream.readObject() without ObjectInputFilter in fabric-sdk-java allows Java deserialization RCE
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.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- 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-2026-41586.
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.
Real-World Exposure
hyperledger-fabric-ordererReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Bitnami packages — download data is not available via public APIs for these ecosystems.
Description
Hyperledger Fabric is an enterprise-grade permissioned distributed ledger framework for developing solutions and applications. From versions 1.0.0 to 2.2.26, Channel.java implements readObject() and exposes deSerializeChannel() which call ObjectInputStream.readObject() on untrusted byte arrays without configuring an ObjectInputFilter. This is a classic Java deserialization RCE pattern. At time of publication, there are no publicly available patches.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦Bitnami | hyperledger-fabric-orderer | ≥ 1.0.0&&< 2.5.9 | 2.5.9 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for hyperledger-fabric-orderer, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update hyperledger-fabric-orderer to 2.5.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-41586 is resolved across your whole dependency graph.
Workarounds
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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-41586 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-41586. 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-2026-41586 in your dependencies?
O3 Security finds CVE-2026-41586 across Bitnami dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.