{"id":"CVE-2026-115935","title":"Control panel only API response emulation replaces \"securityKey\" and reaches server RCE","summary":"The app/process-api-response-headers action accepts fake Craft API response headers from any authenticated control panel user.\n\n\n\nA non-admin user with only accessCp can place newline characters in X-Craft-Plugin-Licenses. Craft passes t…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-94"],"vendor":"craftcms","product":"craftcms/cms","affected":["craftcms/cms >= 5.0.0 < 5.11.2","craftcms/cms >= 4.0.0 < 4.18.9"],"published":"2026-10-23","updated":"2026-10-23","sourceUpdated":"2026-10-23T21:40:57.592Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-115935","references":[{"url":"https://www.hckrt.com/hacktivity/HCKRT-WM3VSE"},{"url":"https://github.com/craftcms/cms/releases/tag/5.11.2"},{"url":"https://github.com/craftcms/cms"},{"url":"https://github.com/craftcms/cms/security/advisories/GHSA-9hp6-3565-gvh5"}],"tags":["cve.org"],"ingestedAt":"2026-10-24T00:46:53.884Z","slug":"CVE-2026-115935","body":"## Overview\n\nThe app/process-api-response-headers action accepts fake Craft API response headers from any authenticated control panel user.\n\n\n\nA non-admin user with only accessCp can place newline characters in X-Craft-Plugin-Licenses. Craft passes this value to its .env writer without removing the newlines.\n\n\n\nThis lets the user insert a new attacker-known CRAFT_SECURITY_KEY into .env. After Craft loads that key, the user can forge a signed login redirect containing a Twig system() callback.\n\n\n\nThis is different from the previous report. That report reads the existing key through a Twig sandbox bypass. This report replaces the key through fake API headers and CRLF injection. Fixing either source does not fix the other.\n\n## Affected\n\n- `craftcms/cms >= 5.0.0 < 5.11.2`\n- `craftcms/cms >= 4.0.0 < 4.18.9`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}