{
  "cveId": "CVE-2021-34813",
  "url": "https://patchblox.com/security/cve/CVE-2021-34813",
  "summary": "CVE-2021-34813 is fixed in 2 products on 1 platform, first by libolm3 3.1.3\u002Bdfsg-2ubuntu0.1~esm1, released June 16, 2021. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "libolm3: Matrix libolm before 3.2.3 allows a malicious Matrix homeserver to crash a client (while it is attempting to retrieve...",
  "description": "Matrix libolm before 3.2.3 allows a malicious Matrix homeserver to crash a client (while it is attempting to retrieve an Olm encrypted room key backup from the homeserver) because olm_pk_decrypt has a stack-based buffer overflow. Remote code execution might be possible for some nonstandard build configurations.",
  "published": "2021-06-16T11:15:00Z",
  "severity": "Medium",
  "epss": 0.04262,
  "epssPercentile": 0.91125,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "libolm3",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "3.1.3\u002Bdfsg-2ubuntu0.1~esm1",
      "fix": "libolm3 3.1.3\u002Bdfsg-2ubuntu0.1~esm1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-libolm3-3.1.3-dfsg-2ubuntu0.1-esm1",
      "released": "2021-06-16T11:15:00Z"
    },
    {
      "platform": "linux",
      "product": "python3-olm",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "3.1.3\u002Bdfsg-2ubuntu0.1~esm1",
      "fix": "python3-olm 3.1.3\u002Bdfsg-2ubuntu0.1~esm1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-python3-olm-3.1.3-dfsg-2ubuntu0.1-esm1",
      "released": "2021-06-16T11:15:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T13:06:02Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}