{
  "cveId": "CVE-2021-21342",
  "url": "https://patchblox.com/security/cve/CVE-2021-21342",
  "summary": "CVE-2021-21342 is fixed in libxstream-java on 1 platform, first by libxstream-java 1.4.11.1-1~18.04.2, released March 22, 2021. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "libxstream-java: XStream is a Java library to serialize objects to XML and back again",
  "description": "XStream is a Java library to serialize objects to XML and back again. InXStream before version 1.4.16, there is a vulnerability where the processedstream at unmarshalling time contains type information to recreate theformerly written objects. XStream creates therefore new instances based onthese type information. An attacker can manipulate the processed inputstream and replace or inject objects, that result in a server-side forgeryrequest. No user is affected, who followed the recommendation to setupXStream\u0027s security framework with a whitelist limited to the minimalrequired types. If you rely on XStream\u0027s default blacklist of the SecurityFramework, you will have to use at least version 1.4.16.",
  "published": "2021-03-22T17:15:00Z",
  "severity": "Medium",
  "epss": 0.4999,
  "epssPercentile": 0.9891,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "libxstream-java",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "1.4.11.1-1~18.04.2",
      "fix": "libxstream-java 1.4.11.1-1~18.04.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-libxstream-java-1.4.11.1-1-18.04.2",
      "released": "2021-03-22T17:15:00Z"
    },
    {
      "platform": "linux",
      "product": "libxstream-java",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "1.4.11.1-1ubuntu0.2",
      "fix": "libxstream-java 1.4.11.1-1ubuntu0.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-libxstream-java-1.4.11.1-1ubuntu0.2",
      "released": "2021-03-22T17:15:00Z"
    },
    {
      "platform": "linux",
      "product": "libxstream-java",
      "release": "Ubuntu 24.10 (oracular)",
      "fixedVersion": "1.4.15-2",
      "fix": "libxstream-java 1.4.15-2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-oracular-libxstream-java-1.4.15-2",
      "released": "2026-01-16T01:42:22Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T13:31:49Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}