CVE-2026-20355Medium· 5.9▾ SunlitMultiple 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. …
▾ Sunlit zone — Low / medium · no exploitation signal
impact 32.5 · likelihood 0 · exploitation 0
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Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake. The CVSS score shown above comes from the assigning CNA record, not NVD.
Exploit-prediction probability, daily snapshots since Sep 8.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via CVEORG
Last analysed / modified upstream
0.1%
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.
These 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.
secure_email 14.0.0-698secure_email 13.5.1-277secure_email 13.0.0-392secure_email 14.2.0-620secure_email 13.0.5-007secure_email 13.5.4-038secure_email 14.2.1-020secure_email 14.3.0-032secure_email 15.0.0-104secure_email 15.0.1-030secure_email 15.5.0-048secure_email 15.5.1-055secure_email 15.5.2-018secure_email 16.0.0-050secure_email 15.0.3-002secure_email 16.0.0-054secure_email 15.5.3-022secure_email 16.0.1-017secure_email 15.5.4-012secure_email 16.0.4-016secure_email 15.0.5-016secure_email 16.0.2-112secure_email 16.0.3-044secure_email 16.5.0-780Refer to the linked advisories for vendor-supplied fixes and affected version ranges.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-20354Medium· 5.9Cisco Secure Email S/MIME Ciphertext Decryption Vulnerabilty
CVE-2026-76440Critical· 9.8As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Secure Email Gateway and Cisco Secure Email and Web Manager engineering team has conducted a comprehensive internal security review
CVE-2026-76443Critical· 9.8As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Secure Email Gateway and Cisco Secure Email and Web Manager engineering team has conducted a comprehensive internal security review
CVE-2026-20353Critical· 9.8As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Secure Email Gateway and Cisco Secure Email and Web Manager engineering team has conducted a comprehensive internal security review
CVE-2026-76442High· 7.5As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Secure Email Gateway and Cisco Secure Email and Web Manager engineering team has conducted a comprehensive internal security review
CVE-2026-20306Critical· 9.1A vulnerability in the REST API of Cisco ISE and ISE-PIC could allow an authenticated, remote attacker to perform command injection attacks on the underlying operating system and elevate privileges to root