{
  "cveId": "CVE-2026-39977",
  "url": "https://patchblox.com/security/cve/CVE-2026-39977",
  "summary": "CVE-2026-39977 is fixed in 2 products on 1 platform, first by flatpak-builder 1.4.8-1, released April 9, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "flatpak-builder: flatpak-builder is a tool to build flatpaks from source",
  "description": "flatpak-builder is a tool to build flatpaks from source. From 1.4.5 to before 1.4.8, the license-files manifest key takes an array of paths to user defined licence files relative to the source directory of the module. The paths from that array are resolved using g_file_resolve_relative_path() and validated to stay inside the source directory using two checks - g_file_get_relative_path() which does not resolve symlinks and g_file_query_file_type() with G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS which only applies to the final path component. The copy operation runs on host. This can be exploited by using a crafted manifest and/or source to read arbitrary files from the host and capture them into the build output. This vulnerability is fixed in 1.4.8.",
  "published": "2026-04-09T13:16:00Z",
  "severity": "medium",
  "cvss": 6.3,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N",
  "epss": 0.00299,
  "epssPercentile": 0.22765,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "flatpak-builder",
      "release": "Debian 14",
      "fixedVersion": "1.4.8-1",
      "fix": "DEBIAN-CVE-2026-39977",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-39977",
      "released": "2026-04-09T20:16:26Z"
    },
    {
      "platform": "linux",
      "product": "flatpak-builder",
      "release": "Ubuntu 26.04.1 LTS (resolute)",
      "fixedVersion": "1.4.8-1",
      "fix": "flatpak-builder 1.4.8-1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-resolute-flatpak-builder-1.4.8-1",
      "released": "2026-04-09T13:16:00Z"
    },
    {
      "platform": "linux",
      "product": "flatpak-builder-tests",
      "release": "Ubuntu 26.04.1 LTS (resolute)",
      "fixedVersion": "1.4.8-1",
      "fix": "flatpak-builder-tests 1.4.8-1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-resolute-flatpak-builder-tests-1.4.8-1",
      "released": "2026-04-09T13:16:00Z"
    }
  ],
  "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"
  }
}