{
  "cveId": "CVE-2026-50538",
  "url": "https://patchblox.com/security/cve/CVE-2026-50538",
  "summary": "CVE-2026-50538 is fixed in 4 products on 1 platform, first by libvncclient1 0.9.15\u002Bdfsg-3ubuntu0.2, released June 14, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "libvncserver: LibVNCClient is a library for easy implementation of a VNC client",
  "description": "LibVNCClient is a library for easy implementation of a VNC client. In versions 0.9.12 through 0.9.15, a malicious (or man-in-the-middle) VNC server can force a connecting \u0060libvncclient\u0060 to write attacker-controlled data past the end of its framebuffer. This is an out-of-bounds heap write with attacker-controlled length, contents, and offset. It needs no authentication (the attacker is the server), works in a default build with default settings, and fires from a single \u0060FramebufferUpdate\u0060 the moment the victim connects. It crashes any client unconditionally (denial of service); we also demonstrated it overwriting an application callback pointer and redirecting execution to attacker-chosen code (code execution) under the default configuration. Commit 540332be3e0acc566fa64da6f1b4680c72c724dd patches the issue.",
  "published": "2026-06-14T17:00:00Z",
  "severity": "high",
  "cvss": 8.8,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
  "epss": 0.00404,
  "epssPercentile": 0.34884,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "LibVNCServer",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "0.9.14-160000.6.1",
      "fix": "OPENSUSE-SU-2026:21735-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21735-1",
      "released": "2026-09-02T09:40:22Z"
    },
    {
      "platform": "linux",
      "product": "LibVNCServer",
      "release": "sles 15.7",
      "fixedVersion": "0.9.14-150600.3.12.1",
      "fix": "SUSE-SU-2026:4022-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-4022-1",
      "released": "2026-09-07T07:42:44Z"
    },
    {
      "platform": "linux",
      "product": "LibVNCServer",
      "release": "sles 16.0",
      "fixedVersion": "0.9.14-160000.6.1",
      "fix": "SUSE-SU-2026:23601-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-23601-1",
      "released": "2026-09-02T09:37:55Z"
    },
    {
      "platform": "linux",
      "product": "libvncclient1",
      "release": "Ubuntu 22.04.1 LTS (jammy)",
      "fixedVersion": "0.9.13\u002Bdfsg-3ubuntu0.2",
      "fix": "libvncclient1 0.9.13\u002Bdfsg-3ubuntu0.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-jammy-libvncclient1-0.9.13-dfsg-3ubuntu0.2",
      "released": "2026-07-03T14:54:52Z"
    },
    {
      "platform": "linux",
      "product": "libvncclient1",
      "release": "Ubuntu 24.04.5 LTS (noble)",
      "fixedVersion": "0.9.14\u002Bdfsg-1ubuntu0.2",
      "fix": "libvncclient1 0.9.14\u002Bdfsg-1ubuntu0.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-noble-libvncclient1-0.9.14-dfsg-1ubuntu0.2",
      "released": "2026-07-03T14:54:55Z"
    },
    {
      "platform": "linux",
      "product": "libvncclient1",
      "release": "Ubuntu 25.10 (questing)",
      "fixedVersion": "0.9.15\u002Bdfsg-1ubuntu0.2",
      "fix": "libvncclient1 0.9.15\u002Bdfsg-1ubuntu0.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-questing-libvncclient1-0.9.15-dfsg-1ubuntu0.2",
      "released": "2026-07-03T14:54:58Z"
    },
    {
      "platform": "linux",
      "product": "libvncclient1",
      "release": "Ubuntu 26.04.1 LTS (resolute)",
      "fixedVersion": "0.9.15\u002Bdfsg-3ubuntu0.2",
      "fix": "libvncclient1 0.9.15\u002Bdfsg-3ubuntu0.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-resolute-libvncclient1-0.9.15-dfsg-3ubuntu0.2",
      "released": "2026-06-14T17:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libvncserver",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "0.9.14\u002Bdfsg-1\u002Bdeb12u2",
      "fix": "DEBIAN-CVE-2026-50538",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-50538",
      "released": "2026-06-24T14:07:24Z"
    },
    {
      "platform": "linux",
      "product": "libvncserver",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "0.9.15\u002Bdfsg-1\u002Bdeb13u2",
      "fix": "DEBIAN-CVE-2026-50538",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-50538",
      "released": "2026-06-24T14:07:24Z"
    },
    {
      "platform": "linux",
      "product": "libvncserver",
      "release": "Debian 14",
      "fixedVersion": "0.9.15\u002Bdfsg-6",
      "fix": "DEBIAN-CVE-2026-50538",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-50538",
      "released": "2026-06-24T14:07:24Z"
    },
    {
      "platform": "linux",
      "product": "libvncserver1",
      "release": "Ubuntu 22.04.1 LTS (jammy)",
      "fixedVersion": "0.9.13\u002Bdfsg-3ubuntu0.2",
      "fix": "libvncserver1 0.9.13\u002Bdfsg-3ubuntu0.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-jammy-libvncserver1-0.9.13-dfsg-3ubuntu0.2",
      "released": "2026-07-03T14:54:52Z"
    },
    {
      "platform": "linux",
      "product": "libvncserver1",
      "release": "Ubuntu 24.04.5 LTS (noble)",
      "fixedVersion": "0.9.14\u002Bdfsg-1ubuntu0.2",
      "fix": "libvncserver1 0.9.14\u002Bdfsg-1ubuntu0.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-noble-libvncserver1-0.9.14-dfsg-1ubuntu0.2",
      "released": "2026-07-03T14:54:55Z"
    },
    {
      "platform": "linux",
      "product": "libvncserver1",
      "release": "Ubuntu 25.10 (questing)",
      "fixedVersion": "0.9.15\u002Bdfsg-1ubuntu0.2",
      "fix": "libvncserver1 0.9.15\u002Bdfsg-1ubuntu0.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-questing-libvncserver1-0.9.15-dfsg-1ubuntu0.2",
      "released": "2026-07-03T14:54:58Z"
    },
    {
      "platform": "linux",
      "product": "libvncserver1",
      "release": "Ubuntu 26.04.1 LTS (resolute)",
      "fixedVersion": "0.9.15\u002Bdfsg-3ubuntu0.2",
      "fix": "libvncserver1 0.9.15\u002Bdfsg-3ubuntu0.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-resolute-libvncserver1-0.9.15-dfsg-3ubuntu0.2",
      "released": "2026-06-14T17:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T01:18:40Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}