{"id":"CVE-2026-100701","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-100701","generatedAt":"2026-10-28T09:27:29.941Z","title":"In multi-tenant services or SNI-routed SMTP gateways, an attacker who can prime the cache can cause a victim transport to connect to the attacker's TLS virtual host and accept the attacker's certificate even with rejectUnauthorized: true, disclosing the…","description":"Nodemailer versions 5.0.0 through 10.0.1 use a process-global DNS cache that is keyed only by the DNS host, while each cache entry also stores the caller-specific TLS servername. When two direct TLS/SMTPS transports (secure: true) resolve the same non-IP host with different tls.servername values, the first transport's servername is returned on the cache hit and overwrites the second transport's explicitly configured value, so Nodemailer sends the wrong SNI value and validates the peer certificate against the wrong identity. In multi-tenant services or SNI-routed SMTP gateways, an attacker who can prime the cache can cause a victim transport to connect to the attacker's TLS virtual host and accept the attacker's certificate even with rejectUnauthorized: true, disclosing the victim's SMTP credentials. Fixed in 10.0.2.","published":"2026-09-26T14:16:55.000Z","lastModified":"2026-09-30T16:32:18.000Z","status":"Awaiting Analysis","sourceIdentifier":"disclosure@vulncheck.com","cvss":{"version":"4.0","score":6,"severity":"MEDIUM","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/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/M"},"cwe":["CWE-295"],"affected":[],"epss":{"score":0.00114,"percentile":0.01494,"date":"2026-10-27","history":[{"date":"2026-09-27","score":0.00114,"percentile":0.01357}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.11%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-26T14:16:55.000Z","detail":{"score":"6.0","severity":"MEDIUM","publishedAt":"2026-09-26T14:16:55.143Z"},"summary":"New CVE, medium severity (CVSS 6.0)."}],"references":[{"url":"https://github.com/nodemailer/nodemailer/security/advisories/GHSA-6vj9-mwq6-2f5v","source":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/nodemailer-5.0.0-through-10.0.1-tls-servername-cache-confusion","source":"disclosure@vulncheck.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-100701","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."}