CVE-2026-21483

{"id": "CVE-2026-21483", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-21483", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-01-02T21:18:17.532399Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 5.4, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "LOW"}, "impactScore": 2.7, "exploitabilityScore": 2.3}], "cvssMetricV40": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 5.4, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:P/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", "exploitMaturity": "PROOF_OF_CONCEPT", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "subIntegrityImpact": "HIGH", "vulnIntegrityImpact": "NONE", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "HIGH", "vulnConfidentialityImpact": "NONE", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "knadh", "product": "listmonk", "versions": [{"status": "affected", "version": "< 6.0.0"}]}]}], "published": "2026-01-02T21:16:03.217", "references": [{"url": "https://github.com/knadh/listmonk/security/advisories/GHSA-jmr4-p576-v565", "tags": ["Exploit", "Vendor Advisory"], "source": "security-advisories@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-79"}]}], "descriptions": [{"lang": "en", "value": "listmonk is a standalone, self-hosted, newsletter and mailing list manager. Prior to version 6.0.0, lower-privileged user with campaign management permissions can inject malicious JavaScript into campaigns or templates. When a higher-privileged user (Super Admin) views or previews this content, the XSS executes in their browser context, allowing the attacker to perform privileged actions such as creating backdoor admin accounts. The attack can be weaponized via the public archive feature, where victims simply need to visit a link - no preview click required. Version 6.0.0 fixes the issue."}, {"lang": "es", "value": "listmonk es un gestor de boletines y listas de correo aut\u00f3nomo y autoalojado. Antes de la versi\u00f3n 6.0.0, un usuario con privilegios inferiores y permisos de gesti\u00f3n de campa\u00f1as puede inyectar JavaScript malicioso en campa\u00f1as o plantillas. Cuando un usuario con privilegios superiores (Super Admin) ve o previsualiza este contenido, el XSS se ejecuta en el contexto de su navegador, permitiendo al atacante realizar acciones privilegiadas como crear cuentas de administrador con puerta trasera. El ataque puede ser instrumentalizado a trav\u00e9s de la funci\u00f3n de archivo p\u00fablico, donde las v\u00edctimas simplemente necesitan visitar un enlace - no se requiere hacer clic en la previsualizaci\u00f3n. La versi\u00f3n 6.0.0 corrige el problema."}], "lastModified": "2026-06-17T10:18:42.023", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:nadh:listmonk:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "41CE03AA-115A-4370-B761-5684D5882B63", "versionEndExcluding": "6.0.0"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}