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Deserialization of Untrusted DataWeakness · CWE-502

CVE-2026-41586

CRITICAL · 9.3 CVSS v4.0 Published 2026-05-07
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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 · unedited
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.

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 confidence

Hyperledger Fabric versions 1.0.0 through 2.2.26 contain a critical Java deserialization vulnerability in Channel.java. The readObject() and deSerializeChannel() methods deserialize untrusted byte arrays via ObjectInputStream.readObject() without configuring an ObjectInputFilter, enabling remote code execution.

MitigationUntil an official patch is released, isolate affected Fabric nodes behind network controls and restrict peer-to-peer communication to trusted entities. Monitor for signs of deserialization gadget exploitation and consider upgrading to version 2.2.27 or later once available.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS 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
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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 checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Hyperledger Fabric installation
    Run 'peer version' or check for fabric peer binaries in the system PATH
    Affected if The peer command executes and returns version information
  2. Identify installed Fabric version
    Execute 'peer version' and note the version string (e.g., 2.2.0, 1.4.12)
    Affected if The version falls within 1.0.0 through 2.2.26 inclusive
  3. Verify peer service network exposure
    Check core.yaml or environment variables (CORE_PEER_LISTENADDRESS, CORE_PEER_ADDRESS) to determine if the peer listens on network interfaces
    Affected if The peer is bound to a non-localhost address or is reachable from other network segments
  4. Check peer-to-peer gossip protocol status
    Examine core.yaml for 'peer.gossip.enabled' setting or verify gossip is active via peer logs
    Affected if Gossip protocol is enabled (default behavior) allowing inter-peer communication
  5. Review peer logs for deserialization activity
    Search peer logs for 'readObject', 'deSerializeChannel', or ObjectInputStream patterns
    Affected if Log entries show incoming serialized channel data from untrusted peers

A user is affected if they run Hyperledger Fabric peer versions 1.0.0 through 2.2.26 with the peer service network-accessible and gossip protocol enabled, as this allows untrusted peers to send malicious serialized objects to the vulnerable readObject() and deSerializeChannel() methods.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Until an official patch is released, isolate affected Fabric nodes behind network controls and restrict peer-to-peer communication to trusted entities. Monitor for signs of deserialization gadget exploitation and consider upgrading to version 2.2.27 or later once available.

Recommended fix High confidence
  1. No remediation steps available as no patch has been released by Hyperledger Fabric maintainers at time of publication
  2. Monitor the official Hyperledger Fabric GitHub repository and security advisories for future patches addressing this deserialization vulnerability
  3. Consider network segmentation and access controls to reduce attack surface until a patch is available
  4. Evaluate potential impact to any systems exposing Fabric network interfaces

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing24.0 h
  • Review / QA12.0 h
60.0 hours of engineering $10,240
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-41586 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data