Craft CMS before 4.18.6 Remote Code Execution via signed cookie
Summary
| CVE | CVE-2026-92592 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-16 22:18:30 UTC |
| Updated | 2026-09-16 22:18:30 UTC |
| Description | Craft CMS 4.8.0 through 4.18.5 and 5.0.0 through 5.10.12 sign an authenticated user's attacker-controlled license-shun cookie with the same key and format used to validate signed redirect parameters, because the HMAC signature is not bound to its purpose (Yii's cookieValidationKey is derived from the same Craft securityKey used for signed request parameters). An authenticated, non-administrator user (Control Panel access is not required) can set the cookie via the license-shun endpoint and transplant the signed envelope into the redirect parameter; on a successful login, Craft validates the signature and renders the authenticated bytes as an unsandboxed Twig template, where Twig's map filter accepts a string callback and allows PHP system() to execute arbitrary operating-system commands as the web-server user. Exploitation requires an account using password authentication without active 2FA, the default request configuration, and availability of PHP system(). The issue is fixed in 4.18.6 and 5.10.13. |
Risk And Classification
Primary CVSS: v4.0 8.7 HIGH from [email protected]
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/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
Problem Types: CWE-1336 | CWE-1336 Improper Neutralization of Special Elements Used in a Template Engine
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 8.7 | HIGH | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 8.7 | HIGH | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| 3.1 | [email protected] | Primary | 8.8 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 8.8 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
LowUser Interaction
NoneConfidentiality
HighIntegrity
HighAvailability
HighSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/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
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/craftcms/cms/security/advisories/GHSA-5r92-75j8-c534 | [email protected] | github.com | |
| www.vulncheck.com/advisories/craft-cms-before-4.18.6-remote-code-execution-via-... | [email protected] | www.vulncheck.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Crypto-Cat (en)
There are currently no legacy QID mappings associated with this CVE.