{
  "cveId": "CVE-2026-27824",
  "url": "https://patchblox.com/security/cve/CVE-2026-27824",
  "summary": "CVE-2026-27824 is fixed in calibre on 1 platform, first by DEBIAN-CVE-2026-27824, released February 27, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "calibre: calibre is a cross-platform e-book manager for viewing, converting, editing, and cataloging e-books",
  "description": "calibre is a cross-platform e-book manager for viewing, converting, editing, and cataloging e-books. Prior to version 9.4.0, the calibre Content Server\u0027s brute-force protection mechanism uses a ban key derived from both \u0060remote_addr\u0060 and the \u0060X-Forwarded-For\u0060 header. Since the \u0060X-Forwarded-For\u0060 header is read directly from the HTTP request without any validation or trusted-proxy configuration, an attacker can bypass IP-based bans by simply changing or adding this header, rendering the brute-force protection completely ineffective. This is particularly dangerous for calibre servers exposed to the internet, where brute-force protection is the primary defense against credential stuffing and password guessing attacks. Version 9.4.0 contains a fix for the issue.",
  "published": "2026-02-27T20:21:39Z",
  "severity": "medium",
  "cvss": 5.3,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
  "epss": 0.00174,
  "epssPercentile": 0.06881,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "calibre",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "6.13.0\u002Brepack-2\u002Bdeb12u6",
      "fix": "DEBIAN-CVE-2026-27824",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-27824",
      "released": "2026-02-27T20:21:39Z"
    },
    {
      "platform": "linux",
      "product": "calibre",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "8.5.0\u002Bds-1\u002Bdeb13u2",
      "fix": "DEBIAN-CVE-2026-27824",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-27824",
      "released": "2026-02-27T20:21:39Z"
    },
    {
      "platform": "linux",
      "product": "calibre",
      "release": "Debian 14",
      "fixedVersion": "9.4.0\u002Bds\u002B~0.10.5-1",
      "fix": "DEBIAN-CVE-2026-27824",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-27824",
      "released": "2026-02-27T20:21:39Z"
    }
  ],
  "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"
  }
}