{
  "cveId": "CVE-2021-31535",
  "url": "https://patchblox.com/security/cve/CVE-2021-31535",
  "summary": "CVE-2021-31535 is fixed in 7 products on 1 platform, first by libx11-6 2:1.6.4-3ubuntu0.4, released May 17, 2021. It is not reported as exploited. Patch Radar priority: High.",
  "title": "libX11-common: The libX11 packages contain the core X11 protocol client library.\n\nSecurity Fix(es):\n\n* libX11: missing request lengt...",
  "description": "The libX11 packages contain the core X11 protocol client library.\n\nSecurity Fix(es):\n\n* libX11: missing request length checks (CVE-2021-31535)\n\nFor more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.\n\nAdditional Changes:\n\nFor detailed information on changes in this release, see the Red Hat Enterprise Linux 8.5 Release Notes linked from the References section.",
  "published": "2021-05-17T17:00:00Z",
  "severity": "Moderate",
  "cvss": 9.8,
  "epss": 0.10353,
  "epssPercentile": 0.95749,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "libX11",
      "release": "RHEL 8",
      "fixedVersion": "0:1.6.8-5.el8",
      "fix": "RHSA-2021:4326",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-4326",
      "released": "2021-11-09T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libX11",
      "release": "ol 8",
      "fixedVersion": "0:1.6.8-5.el8",
      "fix": "ELSA-2021-4326",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-4326",
      "released": "2021-11-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libX11-common",
      "release": "RHEL 8",
      "fixedVersion": "0:1.6.8-5.el8",
      "fix": "RHSA-2021:4326",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-4326",
      "released": "2021-11-09T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libX11-common",
      "release": "ol 8",
      "fixedVersion": "0:1.6.8-5.el8",
      "fix": "ELSA-2021-4326",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-4326",
      "released": "2021-11-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libX11-devel",
      "release": "RHEL 8",
      "fixedVersion": "0:1.6.8-5.el8",
      "fix": "RHSA-2021:4326",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-4326",
      "released": "2021-11-09T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libX11-devel",
      "release": "ol 8",
      "fixedVersion": "0:1.6.8-5.el8",
      "fix": "ELSA-2021-4326",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-4326",
      "released": "2021-11-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libX11-xcb",
      "release": "RHEL 8",
      "fixedVersion": "0:1.6.8-5.el8",
      "fix": "RHSA-2021:4326",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-4326",
      "released": "2021-11-09T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libX11-xcb",
      "release": "ol 8",
      "fixedVersion": "0:1.6.8-5.el8",
      "fix": "ELSA-2021-4326",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-4326",
      "released": "2021-11-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libx11-6",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "2:1.6.4-3ubuntu0.4",
      "fix": "libx11-6 2:1.6.4-3ubuntu0.4",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-libx11-6-2-1.6.4-3ubuntu0.4",
      "released": "2021-05-17T17:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libx11-6",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "2:1.6.9-2ubuntu1.2",
      "fix": "libx11-6 2:1.6.9-2ubuntu1.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-libx11-6-2-1.6.9-2ubuntu1.2",
      "released": "2021-05-17T17:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libx11-data",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "2:1.6.4-3ubuntu0.4",
      "fix": "libx11-data 2:1.6.4-3ubuntu0.4",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-libx11-data-2-1.6.4-3ubuntu0.4",
      "released": "2021-05-17T17:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libx11-data",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "2:1.6.9-2ubuntu1.2",
      "fix": "libx11-data 2:1.6.9-2ubuntu1.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-libx11-data-2-1.6.9-2ubuntu1.2",
      "released": "2021-05-17T17:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libx11-xcb1",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "2:1.6.4-3ubuntu0.4",
      "fix": "libx11-xcb1 2:1.6.4-3ubuntu0.4",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-libx11-xcb1-2-1.6.4-3ubuntu0.4",
      "released": "2021-05-17T17:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libx11-xcb1",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "2:1.6.9-2ubuntu1.2",
      "fix": "libx11-xcb1 2:1.6.9-2ubuntu1.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-libx11-xcb1-2-1.6.9-2ubuntu1.2",
      "released": "2021-05-17T17:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T07:25:28Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}