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.
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)
- 2026-08-01NVD record last updated
CISA Known Exploited Vulnerability
Cisco Secure Firewall Management Center Use of Hard-coded Password Vulnerability
Affected product
Cisco Secure Firewall Management Center (FMC)
Remediation Steps
- Apply the vendor security update for Cisco Secure Firewall Management Center as a priority.
- Restrict network exposure of the affected service to trusted sources until patched.
- Review logs and detections for indicators of exploitation.
- Confirm fixed versions against the official vendor advisory before deploying.
References
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-static-cred-BET3Cjh
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20316
- https://nvd.nist.gov/vuln/detail/CVE-2026-20316
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog
Referenced in our briefings & reports
- Vulnerability Priority Report – Week 2 of August 2026 (August 10 – 16)
- Vulnerability Priority Report – Week 1 of August 2026 (August 3 – 9)
- Vulnerability Priority Report – Week 4 of July 2026 (July 27 – August 2)
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