CVE-2026-20354
A remote, anonymous attacker can exploit multiple vulnerabilities in Cisco AsyncOS and Cisco Secure Email Gateway to bypass security measures.
CSIRTS triage
- What
- Multiple vulnerabilities in Cisco Secure Email Gateway and AsyncOS allow remote anonymous attackers to bypass security measures.
- Who is affected
- Deployments of Cisco Secure Email Gateway handling email traffic.
- Urgency
- Medium severity; security bypass requires prompt patching to prevent unauthorized access.
- Action
- Apply patches for CVE-2026-20354 and CVE-2026-20355 to Cisco Secure Email Gateway.
AI-assisted analysis generated from the source advisory — verify against the original.
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Exploitation outlook
- Low exploitation risk0.15% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 4% of all EPSS-scored CVEs.
Advisory coverage (4)
- medium[NEW] [medium] Cisco Secure Email Gateway: Multiple vulnerabilities enable bypass of security measurescert-bund · 2026-09-03
- mediumCVE-2026-20354: Multiple vulnerabilities in the Secure/Multipurpose Internet Mail Extensions (S/MIME) decrypti…nvd · 2026-09-02
- criticalCisco Advance Notification for Publication of September 2, 2026, Security Advisoriescisco-psirt · 2026-09-02
- mediumCisco Secure Email Secure/Multipurpose Internet Mail Extensions Ciphertext Decryption Vulnerabilitiescisco-psirt · 2026-09-02
External references
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