{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "1.18.1"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "DESCRIPTION"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "abc06c8bf434171e931426e76a9eb0bfe17cfabd"
            }
          ],
          "repo": "https://github.com/flatpak/flatpak",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-8688-9x26-hhxj"
  ],
  "database_specific": {
    "cna_assigner": "mitre",
    "cwe_ids": [
      "CWE-61"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90616.json"
  },
  "details": "In Flatpak before 1.18.1, a malicious sandboxed app can obtain arbitrary read and write access to files on the host, which can be escalated to arbitrary code execution on the host, a different vulnerability than CVE-2026-76925. Flatpak creates a few app data directories (e.g., /var/cache, /var/data, /var/config, and /var/tmp) in every sandbox on every app launch where, in some cases, components of the path are attacker-controlled. Missing symlink protection can redirect the directories. Some of these directories are bind-mounted by Flatpak by passing the path (e.g., /home/user/.var/app/APP_ID/cache/tmp), which contains attacker-controlled directories (tmp) to bwrap --bind SRC DST. bwrap passes the path on to the kernel, which then follows symlinks. A malicious symlink can point to arbitrary locations on the host and it will become mounted inside the sandbox.",
  "id": "CVE-2026-90616",
  "modified": "2026-09-16T03:30:53.410806066Z",
  "published": "2026-09-12T20:00:58.476Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://www.openwall.com/lists/oss-security/2026/08/11/9"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90616.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/flatpak/flatpak/security/advisories/GHSA-8688-9x26-hhxj"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90616"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/flatpak/flatpak"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}