{"id":"CVE-2026-20354","aliases":["EUVD-2026-70210","GHSA-x26v-65cq-x3px"],"status":"published","title":"Cisco Secure Email S/MIME Ciphertext Decryption Vulnerabilty","description":"Multiple vulnerabilities in the Secure/Multipurpose Internet Mail Extensions (S/MIME) decryption functionality of Cisco Secure Email could allow an unauthenticated, remote attacker to recover plain text from encrypted email messages.\r\n\r\nThese vulnerabilities are due to insufficient validation of message integrity. An attacker could exploit these vulnerabilities by using a machine-in-the-middle technique to intercept and modify traffic between email gateways. A successful exploit could allow the attacker to obtain plaintext content from the encrypted communication.","severity":{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00203,"percentile":0.10422,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-354"],"published":"2026-09-02T16:14:29Z","modified":"2026-09-02T19:23:13Z","products":[{"vendor":"cisco","product":"cisco secure email"}],"references":[{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-smime-disc-dzw4rEdY"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-20354"},{"url":"https://github.com/advisories/GHSA-x26v-65cq-x3px"}],"sources":{"cve":[{"id":"CVE-2026-20354","title":"Cisco Secure Email S/MIME Ciphertext Decryption Vulnerabilty","description":"Multiple vulnerabilities in the Secure/Multipurpose Internet Mail Extensions (S/MIME) decryption functionality of Cisco Secure Email could allow an unauthenticated, remote attacker to recover plain text from encrypted email messages.\r\n\r\nThese vulnerabilities are due to insufficient validation of message integrity. An attacker could exploit these vulnerabilities by using a machine-in-the-middle technique to intercept and modify traffic between email gateways. A successful exploit could allow the attacker to obtain plaintext content from the encrypted communication.","status":"published","published":"2026-09-02T16:14:29.829Z","modified":"2026-09-02T17:58:58.074Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-354"],"updated_at":"2026-11-02T13:35:44.571002Z"}],"euvd":[{"id":"EUVD-2026-70210","description":"Multiple vulnerabilities in the Secure/Multipurpose Internet Mail Extensions (S/MIME) decryption functionality of Cisco Secure Email could allow an unauthenticated, remote attacker to recover plain text from encrypted email messages.\r\n\r\nThese vulnerabilities are due to insufficient validation of message integrity. An attacker could exploit these vulnerabilities by using a machine-in-the-middle technique to intercept and modify traffic between email gateways. A successful exploit could allow the attacker to obtain plaintext content from the encrypted communication.","status":"published","published":"2026-09-02T16:14:29Z","modified":"2026-09-02T17:58:58Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T18:01:14.689075Z"}],"ghsa":[{"id":"GHSA-x26v-65cq-x3px","title":"Multiple vulnerabilities in the Secure/Multipurpose Internet Mail Extensions (S/MIME) decryption...","description":"Multiple vulnerabilities in the Secure/Multipurpose Internet Mail Extensions (S/MIME) decryption functionality of Cisco Secure Email could allow an unauthenticated, remote attacker to recover plain text from encrypted email messages.\n\nThese vulnerabilities are due to insufficient validation of message integrity. An attacker could exploit these vulnerabilities by using a machine-in-the-middle technique to intercept and modify traffic between email gateways. A successful exploit could allow the attacker to obtain plaintext content from the encrypted communication.","status":"published","published":"2026-09-02T18:32:27Z","modified":"2026-09-02T18:32:31Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-354"],"updated_at":"2026-11-02T15:11:17.943368Z"}],"nvd":[{"id":"CVE-2026-20354","description":"Multiple vulnerabilities in the Secure/Multipurpose Internet Mail Extensions (S/MIME) decryption functionality of Cisco Secure Email could allow an unauthenticated, remote attacker to recover plain text from encrypted email messages.\r\n\r\nThese vulnerabilities are due to insufficient validation of message integrity. An attacker could exploit these vulnerabilities by using a machine-in-the-middle technique to intercept and modify traffic between email gateways. A successful exploit could allow the attacker to obtain plaintext content from the encrypted communication.","status":"published","published":"2026-09-02T17:17:33.897Z","modified":"2026-09-02T19:23:13.66Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-354"],"updated_at":"2026-11-02T14:12:43.399612Z"}]}}