Answer in brief
CVE-2026-20355 records a Unknown severity vulnerability in Cisco Secure Email S/MIME Ciphertext Decryption Vulnerabilty. The current sources do not mark it as known exploited. The current feed maps Cisco/Cisco Secure Email (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Cisco/Cisco Secure Email (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Cisco/Cisco Secure Emailgeneric | 14.0.0-698 || 13.5.1-277 || 13.0.0-392 || 14.2.0-620 || 13.0.5-007 || 13.5.4-038 || 14.2.1-020 || 14.3.0-032 || 15.0.0-104 || 15.0.1-030 || 15.5.0-048 || 15.5.1-055 || 15.5.2-018 || 16.0.0-050 || 15.0.3-002 || 16.0.0-054 || 15.5.3-022 || 16.0.1-017 || 15.5.4-012 || 16.0.4-016 || 15.0.5-016 || 16.0.2-112 || 16.0.3-044 || 16.5.0-780 | Not reported |
Published upstream
Sep 2, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 2, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 2, 2026
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.
Quoted source text, attributed separately from HOL analysis.