CVE-2026-20316 | defend.network

What is CVE-2026-20316?

A vulnerability in the web interface of Cisco Secure Firewall Management Center (FMC) Software could allow an unauthenticated, remote attacker to log in to an affected device using a low-privileged account to access sensitive data within the impacted systems. This vulnerability is due to the presence of static user credentials for a low-privileged account. An attacker could exploit this vulnerability by using the account to log in to an affected system. A successful exploit could allow the attacker to log in to the affected system and access sensitive data as the low-privileged user. Note: If the FMC management interface does not have public internet access, the attack surface that is associated with this vulnerability is reduced. Cisco has assigned this security advisory a Security Impact Rating (SIR) of High rather than Medium as the score indicates. The reason is that this vulnerability can be used with other Cisco Secure FMC Software vulnerabilities to elevate privileges.

CVSS5.3 NVD 3.1

SeverityMEDIUM

Exploitation In the wild In CISA KEV

Triage statusActive Exploit

ActionPatch immediately

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CWECWE-259

NVD published2026-07-29

NVD last modified2026-07-29

Timeline

2026-07-29Published to the U.S. National Vulnerability Database (NVD)
2026-07-29Added to the CISA Known Exploited Vulnerabilities (KEV) catalog
2026-07-30First covered in a defend.network daily briefing
2026-08-01CISA federal remediation deadline (BOD 22-01)

CISA Known Exploited Vulnerability

Cisco Secure Firewall Management Center Use of Hard-coded Password Vulnerability

Added to KEV2026-07-29

Federal patch deadline2026-08-01

Known ransomware useUnknown

Affected product

Cisco Secure Firewall Management Center (FMC)

Remediation Steps

Apply Cisco's security patch for Secure Firewall Management Center immediately
Rotate all credentials associated with FMC administrative accounts
Review access logs for evidence of unauthorized device access
Restrict network access to FMC to trusted administrative networks only
Enable multi-factor authentication for all FMC administrative accounts

References

Referenced in our briefings & reports

Vulnerability Priority Report – Week 4 of July 2026 (July 27 – August 2)
Critical zero-days in Rails, Ruflo, VMware; Laundry Bear exploits Exchange OWA (2026-07-30)

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🤖 This CVE page is generated by defend.network from NVD, CISA KEV, EPSS, and our verified daily briefings. Severity and exploitation data come from official sources; always verify remediation steps against the official vendor advisory before acting in production.