{"id":"GHSA-94rc-cqvm-m4pw","summary":"Craft CMS Vulnerable to Authenticated RCE via Twig SSTI - create() function + Symfony Process gadget","details":"There is an authenticated admin RCE in Craft CMS 5.8.21 via Server-Side Template Injection using the `create()` Twig function combined with a Symfony Process gadget chain.\n\nThis bypasses the fix implemented for CVE-2025-57811 (patched in 5.8.7).\n\n## Required Permissions\n\n- Administrator permissions or access to System Messages utility\n- `allowAdminChanges` enabled in production ([against our security recommendations](https://craftcms.com/knowledge-base/securing-craft#set-allowAdminChanges-to-false-in-production))  or access to System Messages utility\n\n## Vulnerability Details\nThe `create()` Twig function exposes `Craft::createObject()`, which allows instantiation of arbitrary PHP classes with constructor arguments. Combined with the bundled `symfony/process` dependency, this enables RCE.\n\n## Attack Vector\nAdmin panel → Settings → Entry Types → Title Format field\n\n## Proof of Concept Payload\n\n```\n{% set p = create(\"Symfony\\\\Component\\\\Process\\\\Process\", [[\"id\"]])\n%}{{ p.mustRun.getOutput }}\n```\n\n## Steps to Reproduce\n1. Log in as admin\n2. Navigate to Settings → Entry Types\n3. Edit any entry type’s \"Title Format\" field\n4. Insert the payload above\n5. Create/edit an entry of that type\n6. Command executes, output appears in entry title\n\n## Impact\n- Authenticated Remote Code Execution\n- Runs as web server user (root in default Docker setup)\n- Full server compromise\n\n## Root Cause\nCraft::createObject() allows the instantiation of any class, including\n`Symfony\\Component\\Process\\Process`, which executes shell commands.\n\n## Suggested Fix\n\n- Blocklist dangerous classes in createObject() when called from Twig\n- Or remove/restrict the create() Twig function\n- Or validate class names against an allowlist\n\n## Resources\n\nhttps://github.com/craftcms/cms/commit/e31e50849ad71638e11ea55fbd1ed90ae8f8f6e0","aliases":["CVE-2026-28695"],"modified":"2026-03-04T18:46:15.470209Z","published":"2026-03-03T20:30:36Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2026-03-03T20:30:36Z","nvd_published_at":"2026-03-04T17:16:20Z","cwe_ids":["CWE-1336","CWE-22","CWE-94"],"severity":"MODERATE"},"references":[{"type":"WEB","url":"https://github.com/craftcms/cms/security/advisories/GHSA-94rc-cqvm-m4pw"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-28695"},{"type":"WEB","url":"https://github.com/craftcms/cms/commit/e31e50849ad71638e11ea55fbd1ed90ae8f8f6e0"},{"type":"PACKAGE","url":"https://github.com/craftcms/cms"}],"affected":[{"package":{"name":"craftcms/cms","ecosystem":"Packagist","purl":"pkg:composer/craftcms/cms"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.8.7"},{"fixed":"5.9.0-beta.1"}]}],"versions":["5.8.10","5.8.11","5.8.12","5.8.13","5.8.13.1","5.8.13.2","5.8.14","5.8.15","5.8.16","5.8.17","5.8.18","5.8.19","5.8.20","5.8.21","5.8.22","5.8.23","5.8.7","5.8.8","5.8.9"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-94rc-cqvm-m4pw/GHSA-94rc-cqvm-m4pw.json"}},{"package":{"name":"craftcms/cms","ecosystem":"Packagist","purl":"pkg:composer/craftcms/cms"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0-RC1"},{"fixed":"4.17.0-beta.1"}]}],"versions":["4.0.0","4.0.0-RC1","4.0.0-RC2","4.0.0-RC3","4.0.0.1","4.0.1","4.0.2","4.0.3","4.0.4","4.0.5","4.0.5.1","4.0.5.2","4.0.6","4.1.0","4.1.0.1","4.1.0.2","4.1.1","4.1.2","4.1.3","4.1.4","4.1.4.1","4.10.0","4.10.0-beta.1","4.10.0-beta.2","4.10.1","4.10.2","4.10.3","4.10.4","4.10.5","4.10.6","4.10.7","4.10.8","4.11.0","4.11.0.1","4.11.0.2","4.11.1","4.11.2","4.11.3","4.11.4","4.11.5","4.12.0","4.12.1","4.12.2","4.12.3","4.12.4","4.12.4.1","4.12.5","4.12.6","4.12.6.1","4.12.7","4.12.8","4.12.9","4.13.0","4.13.1","4.13.1.1","4.13.10","4.13.2","4.13.3","4.13.4","4.13.5","4.13.6","4.13.7","4.13.8","4.13.9","4.14.0","4.14.0.1","4.14.0.2","4.14.1","4.14.10","4.14.11","4.14.11.1","4.14.12","4.14.13","4.14.14","4.14.15","4.14.2","4.14.3","4.14.4","4.14.5","4.14.6","4.14.7","4.14.8","4.14.8.1","4.14.9","4.15.0","4.15.0-beta.1","4.15.0-beta.2","4.15.0.1","4.15.0.2","4.15.1","4.15.2","4.15.3","4.15.4","4.15.5","4.15.6","4.15.6.1","4.15.6.2","4.15.7","4.16.0","4.16.1","4.16.10","4.16.11","4.16.12","4.16.13","4.16.14","4.16.15","4.16.16","4.16.17","4.16.18","4.16.19","4.16.2","4.16.3","4.16.4","4.16.5","4.16.6","4.16.6.1","4.16.7","4.16.8","4.16.9","4.16.9.1","4.2.0","4.2.0.1","4.2.0.2","4.2.1","4.2.1.1","4.2.2","4.2.3","4.2.4","4.2.5","4.2.5.1","4.2.5.2","4.2.6","4.2.7","4.2.8","4.3.0","4.3.1","4.3.10","4.3.11","4.3.2","4.3.2.1","4.3.3","4.3.4","4.3.5","4.3.6","4.3.6.1","4.3.7","4.3.7.1","4.3.8","4.3.8.1","4.3.8.2","4.3.9","4.4.0","4.4.0-beta.1","4.4.0-beta.2","4.4.0-beta.3","4.4.0-beta.4","4.4.0-beta.5","4.4.0-beta.6","4.4.0-beta.7","4.4.1","4.4.10","4.4.10.1","4.4.11","4.4.12","4.4.13","4.4.14","4.4.15","4.4.16","4.4.16.1","4.4.17","4.4.2","4.4.3","4.4.4","4.4.5","4.4.6","4.4.6.1","4.4.7","4.4.7.1","4.4.8","4.4.9","4.5.0","4.5.0-beta.1","4.5.0-beta.2","4.5.1","4.5.10","4.5.11","4.5.11.1","4.5.12","4.5.13","4.5.14","4.5.15","4.5.2","4.5.3","4.5.4","4.5.5","4.5.6","4.5.6.1","4.5.7","4.5.8","4.5.9","4.6.0","4.6.0-RC1","4.6.1","4.7.0","4.7.1","4.7.2","4.7.2.1","4.7.3","4.7.4","4.8.0","4.8.1","4.8.10","4.8.11","4.8.2","4.8.3","4.8.4","4.8.5","4.8.6","4.8.7","4.8.8","4.8.9","4.9.0","4.9.1","4.9.2","4.9.3","4.9.4","4.9.5","4.9.6","4.9.7"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-94rc-cqvm-m4pw/GHSA-94rc-cqvm-m4pw.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P"}]}