{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "2.9.2"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "fe7b718d0736f3e139e374e26fbca96f29e13bf0"
            }
          ],
          "repo": "https://github.com/sparkle-project/sparkle",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-hg88-v3cw-3qrh"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-22",
      "CWE-59"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47121.json"
  },
  "details": "Sparkle is a software update framework for macOS. Prior to version 2.9.2, `Autoupdate/SUBinaryDeltaApply.m` enforces `relativePath.pathComponents containsObject:@\"..\"` and rejects writes whose immediate parent directory IS itself a symbolic link, but does not detect symlinks deeper in the relative path. `Autoupdate/SPUSparkleDeltaArchive.m`'s `extractItem:` will create symlinks in the destination tree from archive content (no `..` check on the symlink target), and a subsequent `Extract` item targeting `\u003csymlink\u003e/foo/bar` then escapes the destination tree via `fopen(path, \"wb\")` because the kernel resolves the intermediate symlink during the open call. This is a defense-in-depth issue: exploitation requires a maliciously-crafted `.delta` that passes EdDSA signature verification, i.e. EdDSA private-key compromise. With the AppInstaller running as root for system-domain installs, it gives the holder of a stolen signing key arbitrary file write at root level via the delta-apply path, which is a strictly broader primitive than the \"drop-in replacement bundle\" install they would otherwise have. Version 2.9.2 contains a patch for the issue.",
  "id": "CVE-2026-47121",
  "modified": "2026-07-25T03:56:29.612234896Z",
  "published": "2026-07-21T13:53:05.030Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47121.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/sparkle-project/Sparkle/security/advisories/GHSA-hg88-v3cw-3qrh"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-47121"
    },
    {
      "type": "FIX",
      "url": "https://github.com/sparkle-project/Sparkle/commit/fe7b718d0736f3e139e374e26fbca96f29e13bf0"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Sparkle: Binary delta apply intermediate-symlink traversal in malicious .delta"
}