{"id":"CVE-2026-72695","aliases":["EUVD-2026-65209","GHSA-896w-cw95-xq7w","GHSA-jq29-c7v8-rg55"],"status":"published","title":"Grav before 2.0.16 Path Traversal via MediaUploadTrait deleteFile","description":"Grav before 2.0.16 contains a path traversal vulnerability in MediaUploadTrait::deleteFile() that allows authenticated users with media management permissions to delete arbitrary files by supplying filenames with directory traversal sequences. The method validates only the basename portion of the filename while preserving unvalidated directory paths containing ../ sequences that are passed to unlink(), enabling deletion of files outside the intended media storage directory.","severity":{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00631,"percentile":0.50569,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-22"],"published":"2026-08-25T01:30:11Z","modified":"2026-10-28T02:31:03Z","fixes":[{"ecosystem":"Packagist","package":"getgrav/grav","fixed_in":["2.0.16"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"Packagist","package":"getgrav/grav","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"2.0.15"},{"fixed":"2.0.16"}]}]},{"source":"osv","ecosystem":"Packagist","package":"getgrav/grav","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.0.16"}]}],"versions":["0.8.0","0.9.0","0.9.1","0.9.10","0.9.11","0.9.12","0.9.13","0.9.14","0.9.15","0.9.16","0.9.17","0.9.18","0.9.19","0.9.2","0.9.20","0.9.21","0.9.22","0.9.23","0.9.24","0.9.25","0.9.26","0.9.27","0.9.28","0.9.29","0.9.3","0.9.30","0.9.31","0.9.32","0.9.33","0.9.34","0.9.35","0.9.36","0.9.37","0.9.38","0.9.39","0.9.4","0.9.40","0.9.41","0.9.42","0.9.43","0.9.44","0.9.45","0.9.5","0.9.6","0.9.7","0.9.8","0.9.9","1.0.0","1.0.0-rc.1","1.0.0-rc.2","1.0.0-rc.3","1.0.0-rc.4","1.0.0-rc.5","1.0.0-rc.6","1.0.1","1.0.10","1.0.2","1.0.3","1.0.4","1.0.5","1.0.6","1.0.7","1.0.8","1.0.9","1.1.0","1.1.0-beta.1","1.1.0-beta.2","1.1.0-beta.3","1.1.0-beta.4","1.1.0-beta.5","1.1.0-rc.1","1.1.0-rc.2","1.1.0-rc.3","1.1.1","1.1.10","1.1.11","1.1.12","1.1.13","1.1.14","1.1.15","1.1.16","1.1.17","1.1.2","1.1.3","1.1.4","1.1.5","1.1.6","1.1.7","1.1.8","1.1.9","1.1.9-rc.1","1.1.9-rc.2","1.1.9-rc.3","1.2.0","1.2.0-rc.1","1.2.0-rc.2","1.2.0-rc.3","1.2.1","1.2.2","1.2.3","1.2.4","1.3.0","1.3.0-rc.1","1.3.0-rc.2","1.3.0-rc.3","1.3.0-rc.4","1.3.0-rc.5","1.3.1","1.3.10","1.3.2","1.3.3","1.3.4","1.3.5","1.3.6","1.3.7","1.3.8","1.3.9","1.4.0","1.4.0-beta.1","1.4.0-beta.2","1.4.0-beta.3","1.4.0-rc.1","1.4.0-rc.2","1.4.1","1.4.2","1.4.3","1.4.4","1.4.5","1.4.6","1.4.7","1.4.8","1.5.0","1.5.0-beta.1","1.5.0-beta.2","1.5.0-rc.1","1.5.1","1.5.10","1.5.2","1.5.3","1.5.4","1.5.5","1.5.6","1.5.7","1.5.8","1.5.9","1.6.0","1.6.0-beta.1","1.6.0-beta.2","1.6.0-beta.3","1.6.0-beta.4","1.6.0-beta.5","1.6.0-beta.6","1.6.0-beta.7","1.6.0-beta.8","1.6.0-rc.1","1.6.0-rc.2","1.6.0-rc.3","1.6.0-rc.4","1.6.1","1.6.10","1.6.11","1.6.12","1.6.13","1.6.14","1.6.15","1.6.16","1.6.17","1.6.18","1.6.19","1.6.2","1.6.20","1.6.21","1.6.22","1.6.23","1.6.24","1.6.25","1.6.26","1.6.27","1.6.28","1.6.29","1.6.3","1.6.30","1.6.31","1.6.4","1.6.5","1.6.6","1.6.7","1.6.8","1.6.9","1.7.0","1.7.0-beta.1","1.7.0-beta.10","1.7.0-beta.2","1.7.0-beta.3","1.7.0-beta.4","1.7.0-beta.5","1.7.0-beta.6","1.7.0-beta.7","1.7.0-beta.8","1.7.0-beta.9","1.7.0-rc.1","1.7.0-rc.10","1.7.0-rc.11","1.7.0-rc.12","1.7.0-rc.13","1.7.0-rc.14","1.7.0-rc.15","1.7.0-rc.16","1.7.0-rc.17","1.7.0-rc.18","1.7.0-rc.19","1.7.0-rc.2","1.7.0-rc.20","1.7.0-rc.3","1.7.0-rc.4","1.7.0-rc.5","1.7.0-rc.6","1.7.0-rc.7","1.7.0-rc.8","1.7.0-rc.9","1.7.1","1.7.10","1.7.12","1.7.13","1.7.14","1.7.15","1.7.16","1.7.17","1.7.18","1.7.19","1.7.20","1.7.21","1.7.22","1.7.23","1.7.24","1.7.25","1.7.26","1.7.26.1","1.7.27","1.7.27.1","1.7.28","1.7.29","1.7.29.1","1.7.3","1.7.30","1.7.31","1.7.32","1.7.33","1.7.34","1.7.35","1.7.36","1.7.37","1.7.37.1","1.7.38","1.7.39","1.7.39.1","1.7.39.2","1.7.39.3","1.7.39.4","1.7.4","1.7.40","1.7.41","1.7.41.1","1.7.41.2","1.7.42","1.7.42.1","1.7.42.2","1.7.42.3","1.7.43","1.7.44","1.7.45","1.7.46","1.7.47","1.7.48","1.7.49","1.7.49.1","1.7.49.2","1.7.49.3","1.7.49.4","1.7.49.5","1.7.5","1.7.51","1.7.52","1.7.53","1.7.53.1","1.7.53.2","1.7.53.3","1.7.6","1.7.7","1.7.8","1.7.9","1.8.0-beta.1","1.8.0-beta.10","1.8.0-beta.11","1.8.0-beta.12","1.8.0-beta.13","1.8.0-beta.14","1.8.0-beta.15","1.8.0-beta.16","1.8.0-beta.17","1.8.0-beta.18","1.8.0-beta.19","1.8.0-beta.2","1.8.0-beta.20","1.8.0-beta.21","1.8.0-beta.22","1.8.0-beta.23","1.8.0-beta.24","1.8.0-beta.25","1.8.0-beta.26","1.8.0-beta.27","1.8.0-beta.28","1.8.0-beta.29","1.8.0-beta.3","1.8.0-beta.4","1.8.0-beta.5","1.8.0-beta.6","1.8.0-beta.7","1.8.0-beta.8","1.8.0-beta.9","2.0.0","2.0.0-beta.1","2.0.0-beta.2","2.0.0-beta.3","2.0.0-beta.4","2.0.0-rc.1","2.0.0-rc.10","2.0.0-rc.2","2.0.0-rc.3","2.0.0-rc.4","2.0.0-rc.5","2.0.0-rc.6","2.0.0-rc.7","2.0.0-rc.8","2.0.0-rc.9","2.0.1","2.0.10","2.0.11","2.0.12","2.0.13","2.0.14","2.0.15","2.0.2","2.0.3","2.0.4","2.0.5","2.0.6","2.0.7","2.0.8","2.0.9"]}],"products":[{"vendor":"getgrav","product":"grav"}],"references":[{"url":"https://github.com/getgrav/grav/security/advisories/GHSA-jq29-c7v8-rg55","tags":["vendor-advisory","exploit","advisory","web"]},{"url":"https://www.vulncheck.com/advisories/grav-before-path-traversal-via-mediauploadtrait-deletefile","tags":["third-party-advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72695","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-896w-cw95-xq7w"},{"url":"https://github.com/advisories/GHSA-jq29-c7v8-rg55"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72695.json","tags":["advisory"]},{"url":"https://github.com/getgrav/grav","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-72695","title":"Grav before 2.0.16 Path Traversal via MediaUploadTrait deleteFile","description":"Grav before 2.0.16 contains a path traversal vulnerability in MediaUploadTrait::deleteFile() that allows authenticated users with media management permissions to delete arbitrary files by supplying filenames with directory traversal sequences. The method validates only the basename portion of the filename while preserving unvalidated directory paths containing ../ sequences that are passed to unlink(), enabling deletion of files outside the intended media storage directory.","status":"published","published":"2026-08-25T01:30:11.868Z","modified":"2026-10-08T15:24:20.325Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high","assessor":"cna"},{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:19:52.016971Z"}],"euvd":[{"id":"EUVD-2026-65209","description":"Grav before 2.0.16 contains a path traversal vulnerability in MediaUploadTrait::deleteFile() that allows authenticated users with media management permissions to delete arbitrary files by supplying filenames with directory traversal sequences. The method validates only the basename portion of the filename while preserving unvalidated directory paths containing ../ sequences that are passed to unlink(), enabling deletion of files outside the intended media storage directory.","status":"published","published":"2026-08-25T01:30:11Z","modified":"2026-10-08T15:24:20Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T17:27:31.218078Z"}],"ghsa":[{"id":"GHSA-896w-cw95-xq7w","title":"Duplicate Advisory: Grav: Path Traversal in MediaUploadTrait::deleteFile() Allows Arbitrary File Deletion","description":"### Duplicate Advisory\nThis advisory has been withdrawn because it is a duplicate of GHSA-jq29-c7v8-rg55. This link is maintained to preserve external references.\n\n### Original Description\nGrav before 2.0.16 contains a path traversal vulnerability in MediaUploadTrait::deleteFile() that allows authenticated users with media management permissions to delete arbitrary files by supplying filenames with directory traversal sequences. The method validates only the basename portion of the filename while preserving unvalidated directory paths containing ../ sequences that are passed to unlink(), enabling deletion of files outside the intended media storage directory.","status":"withdrawn","published":"2026-08-25T03:32:09Z","modified":"2026-09-17T20:33:41Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"},{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"high"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:41:18.357514Z"},{"id":"GHSA-jq29-c7v8-rg55","title":"Grav: Path Traversal in MediaUploadTrait::deleteFile() Allows Arbitrary File Deletion","description":"# Path Traversal in MediaUploadTrait::deleteFile() Allows Arbitrary File Deletion\n\n## Summary\n\nA path traversal vulnerability in `MediaUploadTrait::deleteFile()` allows an authenticated user with media management permissions to delete arbitrary files on the server. The method validates only the basename portion of the filename using `Utils::checkFilename()`, while the directory path (which may contain `../` sequences) is preserved and passed unvalidated to `unlink()`. This enables directory escape from the intended media storage path.\n\n## Severity\n\n**High (8.1)** - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H\n\n## CWE\n\nCWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')\n\n## Details\n\nIn `system/src/Grav/Common/Media/Traits/MediaUploadTrait.php`, the `deleteFile()` method (lines 332-365) performs filename validation only on the basename, not the full path:\n\n```php\npublic function deleteFile(string $filename, ?array $settings = null): void\n{\n    $settings = $this-\u003egetUploadSettings($settings);\n    $filesystem = Filesystem::getInstance(false);\n\n    // Line 339-340: Only the BASENAME is validated\n    $basename = $filesystem-\u003ebasename($filename);  // e.g. \"evil.jpg\" from \"../../evil.jpg\"\n    if (!Utils::checkFilename($basename)) {         // passes - no traversal in basename\n        throw new RuntimeException(/* ... */);\n    }\n\n    $path = $settings['destination'] ?? $this-\u003egetPath();\n    // ...\n\n    // Line 353: Full pathname (with traversal) is preserved\n    $pathname = $filesystem-\u003epathname($filename);   // \"../../\"\n\n    // Line 356-357: Traversal path reconstructed\n    [$base, $ext,,] = $this-\u003egetFileParts($basename);\n    $name = \"{$pathname}{$base}.{$ext}\";            // \"../../evil.jpg\"\n\n    // Line 360: Passed to doRemove()\n    $this-\u003edoRemove($name, $path);\n}\n```\n\n`doRemove()` (line 521-582) then calls:\n\n```php\n// Line 538\nunlink(\"{$folder}/{$filename}\");\n// e.g. unlink(\"/var/www/grav/user/pages/mypage/../../config/system.yaml\")\n```\n\n`Utils::checkFilename()` (lines 1022-1044) properly checks for `/`, `\\`, and `..`, but it is applied to `$filesystem-\u003ebasename($filename)` (the last path component only), so traversal sequences in the directory portion are never validated.\n\n### Data flow from user input\n\nThe vulnerability is reachable through the Flex media handling pipeline:\n\n1. `FlexMediaTrait::setUpdatedMedia()` (line 386) iterates form flash data where `$filename` is the array key - user-controlled\n2. For file deletions (`$file` is null, line 396), NO upload validation is performed (the `checkUploadedFile()` call at line 401 only executes when `$file` is truthy)\n3. The raw filename is stored in `$this-\u003e_uploads` at line 414\n4. `saveUpdatedMedia()` (line 499) calls `$media-\u003edeleteFile($filename, $settings)` with the unsanitized filename\n\n### Sibling: renameFile()\n\nThe same pattern exists in `renameFile()` (lines 374-405) which has even weaker validation - it performs NO `checkFilename()` call at all. While `renameFile()` currently has no callers in the core codebase, it is part of the public `MediaUploadInterface` and should be fixed as defense-in-depth.\n\n## Proof of Concept\n\n**Environment**: Grav CMS 2.0.16 with admin plugin\n\nThe attack requires an authenticated admin user with page/media editing permissions (not super-admin).\n\n1. Create a target file:\n```bash\necho \"DELETE_ME\" \u003e /var/www/grav/user/data/target.txt\n```\n\n2. Submit a Flex object form (e.g. page edit) with a crafted media deletion where the filename key contains path traversal:\n\n```\nPOST /admin/pages/mypage/task:save\nContent-Type: multipart/form-data\n\n# The form flash data includes a media deletion entry with key:\n# \"../../data/target.txt\" -\u003e null (deletion marker)\n```\n\n3. When `saveUpdatedMedia()` processes the deletion queue:\n   - `$filename` = `../../data/target.txt`\n   - `deleteFile(\"../../data/target.txt\")` is called\n   - `$basename` = `target.txt` (passes `checkFilename()`)\n   - `$pathname` = `../../data/`\n   - `$name` = `../../data/target.txt`\n   - `doRemove()` calls `unlink(\"/var/www/grav/user/pages/mypage/../../data/target.txt\")`\n   - Which resolves to `unlink(\"/var/www/grav/user/data/target.txt\")`\n\n4. The file is deleted outside the intended media directory.\n\n### Impact\n\nAn authenticated user with media management permissions can:\n- Delete configuration files (`user/config/system.yaml`, `user/config/security.yaml`)\n- Delete other pages' content files\n- Delete authentication-related files (user account YAML files)\n- Cause denial of service by removing critical application files\n- Potentially escalate privileges by removing security configuration\n\n## Suggested Fix\n\nApply `Utils::checkFilename()` to the full `$filename` parameter before decomposing it, or reject any filename containing directory separators or `..` sequences:\n\n```php\npublic function deleteFile(string $filename, ?array $settings = null): void\n{\n    $settings = $this-\u003egetUploadSettings($settings);\n    $filesystem = Filesystem::getInstance(false);\n\n    // Validate the FULL filename, not just the basename\n    if (!Utils::checkFilename($filename)) {\n        throw new RuntimeException(/* ... */);\n    }\n\n    // ... rest unchanged\n}\n```\n\nThe same fix should be applied to `renameFile()` for both `$from` and `$to` parameters.\n\n## References\n\n- Vulnerable file: `system/src/Grav/Common/Media/Traits/MediaUploadTrait.php` lines 332-365, 521-582\n- Caller: `system/src/Grav/Framework/Flex/Traits/FlexMediaTrait.php` lines 386-414, 490-499\n- Sibling: `system/src/Grav/Common/Media/Traits/MediaUploadTrait.php` lines 374-405 (renameFile)\n- Related GHSA: GHSA-g6j3-8jv9-ch5f (path traversal in PagesController::batchCopy - different file, same bug class)\n\n## Disclosure\n\nThis vulnerability was discovered using AI-assisted security research tools.","status":"published","published":"2026-09-17T20:34:05Z","modified":"2026-09-17T20:34:07Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"high"},{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:41:18.357514Z"}],"nvd":[{"id":"CVE-2026-72695","description":"Grav before 2.0.16 contains a path traversal vulnerability in MediaUploadTrait::deleteFile() that allows authenticated users with media management permissions to delete arbitrary files by supplying filenames with directory traversal sequences. The method validates only the basename portion of the filename while preserving unvalidated directory paths containing ../ sequences that are passed to unlink(), enabling deletion of files outside the intended media storage directory.","status":"published","published":"2026-08-25T02:16:45.097Z","modified":"2026-10-12T15:10:00.207Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:12:41.018848Z"}],"osv":[{"id":"CVE-2026-72695","title":"Grav before 2.0.16 Path Traversal via MediaUploadTrait deleteFile","description":"Grav before 2.0.16 contains a path traversal vulnerability in MediaUploadTrait::deleteFile() that allows authenticated users with media management permissions to delete arbitrary files by supplying filenames with directory traversal sequences. The method validates only the basename portion of the filename while preserving unvalidated directory paths containing ../ sequences that are passed to unlink(), enabling deletion of files outside the intended media storage directory.","status":"published","published":"2026-08-25T01:30:11.868Z","modified":"2026-10-28T02:31:03.665118624Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T15:45:15.88521Z"},{"id":"GHSA-896w-cw95-xq7w","title":"Duplicate Advisory: Grav: Path Traversal in MediaUploadTrait::deleteFile() Allows Arbitrary File Deletion","description":"### Duplicate Advisory\nThis advisory has been withdrawn because it is a duplicate of GHSA-jq29-c7v8-rg55. This link is maintained to preserve external references.\n\n### Original Description\nGrav before 2.0.16 contains a path traversal vulnerability in MediaUploadTrait::deleteFile() that allows authenticated users with media management permissions to delete arbitrary files by supplying filenames with directory traversal sequences. The method validates only the basename portion of the filename while preserving unvalidated directory paths containing ../ sequences that are passed to unlink(), enabling deletion of files outside the intended media storage directory.","status":"withdrawn","published":"2026-08-25T03:32:09Z","modified":"2026-09-17T20:45:05.783948227Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"high"},{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T15:46:42.077781Z"},{"id":"GHSA-jq29-c7v8-rg55","title":"Grav: Path Traversal in MediaUploadTrait::deleteFile() Allows Arbitrary File Deletion","description":"# Path Traversal in MediaUploadTrait::deleteFile() Allows Arbitrary File Deletion\n\n## Summary\n\nA path traversal vulnerability in `MediaUploadTrait::deleteFile()` allows an authenticated user with media management permissions to delete arbitrary files on the server. The method validates only the basename portion of the filename using `Utils::checkFilename()`, while the directory path (which may contain `../` sequences) is preserved and passed unvalidated to `unlink()`. This enables directory escape from the intended media storage path.\n\n## Severity\n\n**High (8.1)** - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H\n\n## CWE\n\nCWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')\n\n## Details\n\nIn `system/src/Grav/Common/Media/Traits/MediaUploadTrait.php`, the `deleteFile()` method (lines 332-365) performs filename validation only on the basename, not the full path:\n\n```php\npublic function deleteFile(string $filename, ?array $settings = null): void\n{\n    $settings = $this-\u003egetUploadSettings($settings);\n    $filesystem = Filesystem::getInstance(false);\n\n    // Line 339-340: Only the BASENAME is validated\n    $basename = $filesystem-\u003ebasename($filename);  // e.g. \"evil.jpg\" from \"../../evil.jpg\"\n    if (!Utils::checkFilename($basename)) {         // passes - no traversal in basename\n        throw new RuntimeException(/* ... */);\n    }\n\n    $path = $settings['destination'] ?? $this-\u003egetPath();\n    // ...\n\n    // Line 353: Full pathname (with traversal) is preserved\n    $pathname = $filesystem-\u003epathname($filename);   // \"../../\"\n\n    // Line 356-357: Traversal path reconstructed\n    [$base, $ext,,] = $this-\u003egetFileParts($basename);\n    $name = \"{$pathname}{$base}.{$ext}\";            // \"../../evil.jpg\"\n\n    // Line 360: Passed to doRemove()\n    $this-\u003edoRemove($name, $path);\n}\n```\n\n`doRemove()` (line 521-582) then calls:\n\n```php\n// Line 538\nunlink(\"{$folder}/{$filename}\");\n// e.g. unlink(\"/var/www/grav/user/pages/mypage/../../config/system.yaml\")\n```\n\n`Utils::checkFilename()` (lines 1022-1044) properly checks for `/`, `\\`, and `..`, but it is applied to `$filesystem-\u003ebasename($filename)` (the last path component only), so traversal sequences in the directory portion are never validated.\n\n### Data flow from user input\n\nThe vulnerability is reachable through the Flex media handling pipeline:\n\n1. `FlexMediaTrait::setUpdatedMedia()` (line 386) iterates form flash data where `$filename` is the array key - user-controlled\n2. For file deletions (`$file` is null, line 396), NO upload validation is performed (the `checkUploadedFile()` call at line 401 only executes when `$file` is truthy)\n3. The raw filename is stored in `$this-\u003e_uploads` at line 414\n4. `saveUpdatedMedia()` (line 499) calls `$media-\u003edeleteFile($filename, $settings)` with the unsanitized filename\n\n### Sibling: renameFile()\n\nThe same pattern exists in `renameFile()` (lines 374-405) which has even weaker validation - it performs NO `checkFilename()` call at all. While `renameFile()` currently has no callers in the core codebase, it is part of the public `MediaUploadInterface` and should be fixed as defense-in-depth.\n\n## Proof of Concept\n\n**Environment**: Grav CMS 2.0.16 with admin plugin\n\nThe attack requires an authenticated admin user with page/media editing permissions (not super-admin).\n\n1. Create a target file:\n```bash\necho \"DELETE_ME\" \u003e /var/www/grav/user/data/target.txt\n```\n\n2. Submit a Flex object form (e.g. page edit) with a crafted media deletion where the filename key contains path traversal:\n\n```\nPOST /admin/pages/mypage/task:save\nContent-Type: multipart/form-data\n\n# The form flash data includes a media deletion entry with key:\n# \"../../data/target.txt\" -\u003e null (deletion marker)\n```\n\n3. When `saveUpdatedMedia()` processes the deletion queue:\n   - `$filename` = `../../data/target.txt`\n   - `deleteFile(\"../../data/target.txt\")` is called\n   - `$basename` = `target.txt` (passes `checkFilename()`)\n   - `$pathname` = `../../data/`\n   - `$name` = `../../data/target.txt`\n   - `doRemove()` calls `unlink(\"/var/www/grav/user/pages/mypage/../../data/target.txt\")`\n   - Which resolves to `unlink(\"/var/www/grav/user/data/target.txt\")`\n\n4. The file is deleted outside the intended media directory.\n\n### Impact\n\nAn authenticated user with media management permissions can:\n- Delete configuration files (`user/config/system.yaml`, `user/config/security.yaml`)\n- Delete other pages' content files\n- Delete authentication-related files (user account YAML files)\n- Cause denial of service by removing critical application files\n- Potentially escalate privileges by removing security configuration\n\n## Suggested Fix\n\nApply `Utils::checkFilename()` to the full `$filename` parameter before decomposing it, or reject any filename containing directory separators or `..` sequences:\n\n```php\npublic function deleteFile(string $filename, ?array $settings = null): void\n{\n    $settings = $this-\u003egetUploadSettings($settings);\n    $filesystem = Filesystem::getInstance(false);\n\n    // Validate the FULL filename, not just the basename\n    if (!Utils::checkFilename($filename)) {\n        throw new RuntimeException(/* ... */);\n    }\n\n    // ... rest unchanged\n}\n```\n\nThe same fix should be applied to `renameFile()` for both `$from` and `$to` parameters.\n\n## References\n\n- Vulnerable file: `system/src/Grav/Common/Media/Traits/MediaUploadTrait.php` lines 332-365, 521-582\n- Caller: `system/src/Grav/Framework/Flex/Traits/FlexMediaTrait.php` lines 386-414, 490-499\n- Sibling: `system/src/Grav/Common/Media/Traits/MediaUploadTrait.php` lines 374-405 (renameFile)\n- Related GHSA: GHSA-g6j3-8jv9-ch5f (path traversal in PagesController::batchCopy - different file, same bug class)\n\n## Disclosure\n\nThis vulnerability was discovered using AI-assisted security research tools.","status":"published","published":"2026-09-17T20:34:05Z","modified":"2026-09-17T20:45:05.940427846Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"high"},{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T15:46:50.687609Z"}]}}