{"id":"CVE-2026-84465","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-84465","generatedAt":"2026-10-28T01:04:30.937Z","title":"An attacker can create their own certificate using the name of a real, previously trusted sender and use it to send a forged email.","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.","published":"2026-09-25T19:17:58.000Z","lastModified":"2026-09-29T19:17:27.000Z","status":"Deferred","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"4.0","score":7.1,"severity":"HIGH","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-290","CWE-295","CWE-347"],"affected":[],"epss":{"score":0.00124,"percentile":0.02088,"date":"2026-10-26","history":[{"date":"2026-09-26","score":0.00124,"percentile":0.01811}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.12%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-25T19:17:58.000Z","detail":{"score":"7.1","severity":"HIGH","publishedAt":"2026-09-25T19:17:58.123Z"},"summary":"New CVE, high severity (CVSS 7.1)."}],"references":[{"url":"https://github.com/zammad/zammad/commit/9a07d0b8214ac4e8e10c23fce71d613bd0625524","source":"security-advisories@github.com"},{"url":"https://github.com/zammad/zammad/security/advisories/GHSA-m9ff-hjr3-93h4","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-84465","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}