CVE-2026-34718

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{"affected": [{"affectedData": [{"product": "zammad", "vendor": "zammad", "versions": [{"status": "affected", "version": "< 6.5.4"}, {"status": "affected", "version": ">= 7.0.0-alpha, < 7.0.1"}]}], "source": "security-advisories@github.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:zammad:zammad:*:*:*:*:*:*:*:*", "matchCriteriaId": "5AC4AB35-4DD1-43F8-B481-27640E70CF8A", "versionEndExcluding": "6.5.4", "vulnerable": true}, {"criteria": "cpe:2.3:a:zammad:zammad:7.0.0:*:*:*:*:*:*:*", "matchCriteriaId": "830AF7C5-9441-4C80-935E-C53BDB097BB1", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.1 and 6.5.4, the HTML sanitizer for ticket articles was missing proper sanitization of data: ... URI schemes, resulting in storing such malicious content in the database of the Zammad instance. The Zammad GUI is rendering this content, due to applied CSP rules no harm was done by e.g., clicking such a link. This vulnerability is fixed in 7.0.1 and 6.5.4."}, {"lang": "es", "value": "Zammad es un sistema de mesa de ayuda/soporte al cliente de c\u00f3digo abierto basado en web. Antes de las versiones 7.0.1 y 6.5.4, el saneador HTML para art\u00edculos de tickets carec\u00eda de una sanitizaci\u00f3n adecuada de los datos: ... esquemas URI, lo que resultaba en el almacenamiento de dicho contenido malicioso en la base de datos de la instancia de Zammad. La interfaz gr\u00e1fica de usuario (GUI) de Zammad renderiza este contenido, debido a las reglas CSP aplicadas no se caus\u00f3 ning\u00fan da\u00f1o, por ejemplo, al hacer clic en dicho enlace. Esta vulnerabilidad est\u00e1 corregida en las versiones 7.0.1 y 6.5.4."}], "id": "CVE-2026-34718", "lastModified": "2026-07-24T22:10:00.140", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.1, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 2.7, "source": "nvd@nist.gov", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 5.3, "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": "PASSIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/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": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-34718", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-04-08T19:51:13.052875Z", "version": "2.0.3"}}]}, "published": "2026-04-08T19:25:21.863", "references": [{"source": "security-advisories@github.com", "tags": ["Vendor Advisory"], "url": "https://github.com/zammad/zammad/security/advisories/GHSA-c2cf-9fc7-jhf3"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-80"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,6.5.4)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[7.0.0-alpha,7.0.1)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "zammad", "source": "cna", "vendor": "zammad"}, "product": "zammad", "vendor": "zammad"}], "analysis": {"en": {"generated_at": "2026-04-08T19:52:15.612038+00:00", "value": {"mitigation_remediation": ["Back up the Zammad database and configuration", "Upgrade the Zammad installation to version 7.0.1 or 6.5.4, which contains the HTML sanitizer fix", "Verify that ticket articles no longer accept or render unsanitized script tags", "If upgrading immediately is not possible, restrict user permissions to prevent ticket article creation until a patch is applied"], "summary": {"action": "Patch", "impact": "Stored XSS via unsanitized ticket articles"}, "threat_synthesis": {"affected_systems": "The affected product is Zammad, the web\u2011based helpdesk system released by the zammad project. Only installations running versions older than 7.0.1 or 6.5.4 are vulnerable; newer releases contain the fix.", "description_and_impact": "Zammad versions before 7.0.1 and 6.5.4 fail to properly neutralize script\u2011related HTML tags in ticket articles, allowing storage of malicious content in the database. When rendered in the GUI, the content is displayed without sufficient filtering, creating a stored cross\u2011site scripting risk. Although the current CSP rules limit the harm of clicking links, an attacker could potentially inject scripts that run in the context of any user who views the affected ticket, leading to data theft or session hijacking.", "risk_and_exploitability": "With a CVSS score of 5.3 the vulnerability is considered moderate severity. No EPSS score is available, and it is not listed in CISA\u2019s KEV catalog, indicating limited evidence of active exploitation. Based on the description, the likely attack vector is through the web interface: an attacker can submit malicious ticket content which is then stored and later rendered for other users. The exploitation requires the ability to create or edit ticket articles, so it is limited to users with that privilege, but within that scope the impact is significant."}}}}, "created": "2026-04-08T19:55:18.827403+00:00", "updated": "2026-04-08T20:12:41.318863+00:00", "vendors": ["zammad", "zammad$PRODUCT$zammad"]}