{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-75872", "assignerOrgId": "4daa8cea-433a-44bd-9456-53b127fc289a", "state": "PUBLISHED", "assignerShortName": "Secur0", "dateReserved": "2026-08-18T12:20:39.352Z", "datePublished": "2026-08-18T14:06:37.102Z", "dateUpdated": "2026-08-18T14:06:37.102Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "4daa8cea-433a-44bd-9456-53b127fc289a", "shortName": "Secur0", "dateUpdated": "2026-08-18T14:06:37.102Z"}, "title": "HTML Injection in MailerUp double opt-in verification email", "datePublic": "2026-08-18T12:43:00.000Z", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-80", "description": "CWE-80 Improper neutralization of Script-Related HTML tags in a web page (basic XSS)", "type": "CWE"}]}], "impacts": [{"capecId": "CAPEC-242", "descriptions": [{"lang": "en", "value": "CAPEC-242 Code Injection"}]}], "affected": [{"vendor": "maalfer", "product": "MailerUp", "repo": "https://github.com/maalfer/mailerup", "modules": ["Public subscription form"], "programFiles": ["backend/apps/forms/views.py"], "versions": [{"status": "affected", "version": "0", "lessThan": "1.1.3", "versionType": "semver"}], "defaultStatus": "unaffected"}], "cpeApplicability": [{"operator": "OR", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:maalfer:mailerup:*:*:*:*:*:*:*:*", "versionStartIncluding": "0", "versionEndExcluding": "1.1.3"}]}]}], "descriptions": [{"lang": "en", "value": "HTML Injection in the public subscription form in maalfer MailerUp before 1.1.3 allows unauthenticated remote attackers to have the application send a message carrying arbitrary HTML, to an attacker-chosen address and from the form owner's configured sending identity, via the first_name field of the subscription request, which is interpolated unescaped into the double opt-in verification email.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "HTML Injection in the public subscription form in maalfer MailerUp before 1.1.3 allows unauthenticated remote attackers to have the application send a message carrying arbitrary HTML, to an attacker-chosen address and from the form owner's configured sending identity, via the first_name field of the subscription request, which is interpolated unescaped into the double opt-in verification email."}]}], "tags": ["x_open-source"], "references": [{"url": "https://github.com/maalfer/mailerup/commit/da4aedc9621911df4ce0cc8f0b321dd6d10f40a5", "tags": ["patch"]}, {"url": "https://github.com/maalfer/mailerup/releases/tag/v1.1.3", "tags": ["release-notes"]}, {"url": "https://secur0.com/en/cna/cve-list/cve-2026-75872-html-injection-in-mailerup-double-optin-verification-email", "tags": ["technical-description"]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "subConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW", "subIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "version": "4.0", "baseSeverity": "MEDIUM", "baseScore": 6.9, "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N"}}], "solutions": [{"lang": "en", "value": "Upgrade to version 1.1.3 or higher.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<strong></strong> Upgrade to version 1.1.3 or higher."}]}], "credits": [{"lang": "en", "value": "Nacho Garc\u00eda Egea", "type": "finder"}, {"lang": "en", "value": "Xo\u00e1n M. Otero Jorge", "type": "analyst"}, {"lang": "en", "value": "Secur0 CNA", "type": "coordinator"}, {"lang": "en", "value": "Mario \u00c1lvarez Fern\u00e1ndez", "type": "remediation developer"}], "source": {"discovery": "UNKNOWN"}, "x_generator": {"engine": "Vulnogram 1.0.4"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "modules": ["Public subscription form"], "product": "MailerUp", "programFiles": ["backend/apps/forms/views.py"], "repo": "https://github.com/maalfer/mailerup", "vendor": "maalfer", "versions": [{"lessThan": "1.1.3", "status": "affected", "version": "0", "versionType": "semver"}]}], "source": "4daa8cea-433a-44bd-9456-53b127fc289a"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "HTML Injection in the public subscription form in maalfer MailerUp before 1.1.3 allows unauthenticated remote attackers to have the application send a message carrying arbitrary HTML, to an attacker-chosen address and from the form owner's configured sending identity, via the first_name field of the subscription request, which is interpolated unescaped into the double opt-in verification email."}], "id": "CVE-2026-75872", "lastModified": "2026-08-18T15:17:15.150", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 6.9, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/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", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "4daa8cea-433a-44bd-9456-53b127fc289a", "type": "Secondary"}]}, "published": "2026-08-18T15:17:15.150", "references": [{"source": "4daa8cea-433a-44bd-9456-53b127fc289a", "url": "https://github.com/maalfer/mailerup/commit/da4aedc9621911df4ce0cc8f0b321dd6d10f40a5"}, {"source": "4daa8cea-433a-44bd-9456-53b127fc289a", "url": "https://github.com/maalfer/mailerup/releases/tag/v1.1.3"}, {"source": "4daa8cea-433a-44bd-9456-53b127fc289a", "url": "https://secur0.com/en/cna/cve-list/cve-2026-75872-html-injection-in-mailerup-double-optin-verification-email"}], "sourceIdentifier": "4daa8cea-433a-44bd-9456-53b127fc289a", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-80"}], "source": "4daa8cea-433a-44bd-9456-53b127fc289a", "type": "Secondary"}]}

{}

{}