{"id":"CVE-2026-84465","published":"2026-09-25T19:17:58.123","lastModified":"2026-09-29T19:17:27.050","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.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":["CWE-290","CWE-295","CWE-347"],"vendors":[],"products":[],"references":[{"url":"https://github.com/zammad/zammad/commit/9a07d0b8214ac4e8e10c23fce71d613bd0625524","tags":[]},{"url":"https://github.com/zammad/zammad/security/advisories/GHSA-m9ff-hjr3-93h4","tags":[]}],"exploitRefs":[{"url":"https://github.com/zammad/zammad/commit/9a07d0b8214ac4e8e10c23fce71d613bd0625524","tags":[]},{"url":"https://github.com/zammad/zammad/security/advisories/GHSA-m9ff-hjr3-93h4","tags":[]}],"hasPoc":true,"ai":null}