{
  "cveId": "CVE-2020-26258",
  "url": "https://patchblox.com/security/cve/CVE-2020-26258",
  "summary": "CVE-2020-26258 is fixed in libxstream-java on 1 platform, first by libxstream-java 1.4.11.1-1~18.04.1, released December 15, 2020. 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. In XStream before version 1.4.15, a Server-Side Forgery Request vulnerability can be activated when unmarshalling. The vulnerability may allow a remote attacker to request data from internal resources that are not publicly available only by manipulating the processed input stream. If you rely on XStream\u0027s default blacklist of the Security Framework, you will have to use at least version 1.4.15. The reported vulnerability does not exist if running Java 15 or higher. No user is affected who followed the recommendation to setup XStream\u0027s Security Framework with a whitelist! Anyone relying on XStream\u0027s default blacklist can immediately switch to a whilelist for the allowed types to avoid the vulnerability. Users of XStream 1.4.14 or below who still want to use XStream default blacklist can use a workaround described in more detailed in the referenced advisories.",
  "published": "2020-12-15T17:15:00Z",
  "severity": "Medium",
  "epss": 0.81817,
  "epssPercentile": 0.99648,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "libxstream-java",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "1.4.11.1-1~18.04.1",
      "fix": "libxstream-java 1.4.11.1-1~18.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-libxstream-java-1.4.11.1-1-18.04.1",
      "released": "2020-12-15T17:15:00Z"
    },
    {
      "platform": "linux",
      "product": "libxstream-java",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "1.4.11.1-1ubuntu0.1",
      "fix": "libxstream-java 1.4.11.1-1ubuntu0.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-libxstream-java-1.4.11.1-1ubuntu0.1",
      "released": "2020-12-15T17:15:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T00:53:09Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}