{"id":"CVE-2026-84465","revision":"f499fb6aa0264407bbb038156ac23cc4","records":[{"revision":"f499fb6aa0264407bbb038156ac23cc4","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-84465","aliases":[],"title":"Zammad: S/MIME signature verification allows forged sender impersonation","description":"Zammad is a web based open source helpdesk/customer support system. Prior to 7.1.2, when Zammad checks the digital signature on an incoming S/MIME-signed email, it does not verify that the signing certificate is genuinely trusted, it only checks whether a certificate with a matching name is already stored in the system. An attacker can create their own certificate using the name of a real, previously trusted sender and use it to send a forged email. Zammad will display that email with the same \"validly signed\" indicator as a genuine message from the real sender, even though the attacker never had access to that sender's actual certificate or private key. This issue is fixed in version 7.1.2.","state":0,"publishedAt":"2026-09-25T18:19:58.735+00:00","modifiedAt":"2026-09-29T18:08:05.375+00:00","affected":[{"ecosystem":"Vendor product","name":"zammad","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"zammad\",\n                    \"product\": \"zammad\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 7.1.2\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","score":7.1,"severity":"HIGH"}],"references":["https://github.com/zammad/zammad/security/advisories/GHSA-m9ff-hjr3-93h4","https://github.com/zammad/zammad/commit/9a07d0b8214ac4e8e10c23fce71d613bd0625524"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-84465","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-84465","identifiers":["CVE-2026-84465"]},"retained":false,"historicalAffected":[]}],"coverage":[]}