{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.hyperledger.fabric-sdk-java:fabric-sdk-java"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.0.0"
            },
            {
              "last_affected": "2.2.26"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-41586"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-502"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-29T20:41:58Z",
    "nvd_published_at": null,
    "severity": "CRITICAL"
  },
  "details": "## Summary\n\nThis advisory covers the deprecated `fabric-sdk-java` client SDK. `Channel.java` implements `readObject()` and exposes `deSerializeChannel()` which call `ObjectInputStream.readObject()` on untrusted byte arrays without configuring an `ObjectInputFilter`. This is the classic Java deserialization RCE pattern.\n\n**Note:** `fabric-sdk-java` is deprecated and maintained in https://github.com/hyperledger/fabric-sdk-java. Filing here as that repo does not have private vulnerability reporting enabled.\n\n## Affected Code\n\n```java\n// src/main/java/org/hyperledger/fabric/sdk/Channel.java\nprivate void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {\n    in.defaultReadObject();  // No ObjectInputFilter configured\n}\n\npublic Channel deSerializeChannel(byte[] channelBytes)\n        throws IOException, ClassNotFoundException, InvalidArgumentException {\n    ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(channelBytes));\n    Channel channel = (Channel) ois.readObject();  // Untrusted bytes deserialized\n    return channel;\n}\n```\n\n## Attack Vector\n\nAn attacker who can supply crafted serialized Channel bytes to the client application \u2014 for example, by compromising a local channel file, injecting data through an application that accepts Channel bytes from external sources, or exploiting a separate write primitive \u2014 can achieve RCE via gadget chain exploitation when deSerializeChannel() processes those bytes. The risk is highest in deployments that accept Channel data from sources outside the client\u0027s direct control. Note: channel data is not transmitted from Fabric peers; this is a client-side deserialization surface.\n\n## Proof of Concept\n\n```java\n// Generate malicious payload with ysoserial:\n// java -jar ysoserial.jar CommonsCollections6 \"touch /tmp/pwned\" \u003e malicious_channel.ser\n\n// Victim code:\nbyte[] maliciousBytes = Files.readAllBytes(Paths.get(\"malicious_channel.ser\"));\nChannel channel = client.deSerializeChannel(maliciousBytes);  // RCE fires here\n```\n\n## Notes on Deprecation\n\nfabric-sdk-java is deprecated as of Hyperledger Fabric v2.5 (replaced by `org.hyperledger.fabric:fabric-gateway`). However, organizations that have not yet migrated remain fully exposed. Automated dependency scanners (Snyk, Dependabot) cannot alert users without a published GHSA. This advisory is filed to ensure those users are notified and directed to migrate.\n\n## Fix\n\nFor the deprecated SDK: add `ObjectInputFilter` to whitelist only expected classes:\n\n```java\nObjectInputFilter filter = ObjectInputFilter.Config.createFilter(\n    \"org.hyperledger.fabric.sdk.*;java.util.*;java.lang.*;!*\"\n);\nois.setObjectInputFilter(filter);\n```\n\n**The recommended remediation is migration to `org.hyperledger.fabric:fabric-gateway`**, which does not use Java serialization.\n\n## Resources\n\n- CWE-502: Deserialization of Untrusted Data\n- Migration guide: https://hyperledger.github.io/fabric-gateway/\n\n## Credits\n\nFound via independent security research.",
  "id": "GHSA-prf8-cf2x-rhx7",
  "modified": "2026-04-29T20:41:58Z",
  "published": "2026-04-29T20:41:58Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/hyperledger/fabric/security/advisories/GHSA-prf8-cf2x-rhx7"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/hyperledger/fabric"
    },
    {
      "type": "WEB",
      "url": "https://hyperledger.github.io/fabric-gateway"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "fabric-sdk-java has ObjectInputStream.readObject() without ObjectInputFilter, which allows Java deserialization RCE"
}