CVE-2026-20316Cisco Secure Firewall Management Center Use of Hard-coded Password Vulnerability
CVE-2026-20316 is a hard-coded password in Cisco Secure Firewall Management Center (FMC), rated medium (5.3 on CVSS 3.1).
Why this priority: Exploited in the wild: listed in CISA's KEV catalog.
Published · Updated · NVD status: Analyzed
What it is
A password is built into the product and is the same on every install.
How it is reached
An attacker can exploit it over the network, without an account, and nobody has to click anything.
What an attacker gains
The direct impact is limited: partial access to data or a partial outage. In practice, this kind of flaw lets an attacker sign in with credentials the vendor shipped or stored unprotected.
Is it being exploited?
CISA added it to the Known Exploited Vulnerabilities catalog on 2026-07-29: it is being exploited in the wild. CISA links it to ransomware campaigns. It can be exploited automatically, at scale. EPSS estimates a 35% chance of exploitation activity in the next 30 days, higher than 98% of scored CVEs.
What to do
- Treat it as urgent: it is on CISA's KEV list. CISA's deadline for US federal agencies: 2026-08-01.
- No fixed version is listed yet. Find every place Cisco Secure Firewall Management Center (FMC) runs, watch the references for a fix, and plan a replacement if it is no longer supported.
- While there is no fix, keep it off the internet or behind a VPN, allowlist or authenticating proxy.
- Check exposed instances for signs of compromise, not only for the version.
Description from NVD
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.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- Network edge devices: VPNs, firewalls, routers and gateways. They sit between the internet and internal networks, so a flaw in one is often the first step into everything behind it.
- Credentials kept in code, configuration, images or firmware. The flaw sits between a stored secret and anyone who can read where it is kept.
Trust boundaries in play
- Internet-facing entry points. No account is needed. Any instance reachable from outside your perimeter, through a load balancer, gateway, VPN or exposed admin port, is in scope.
- Between a stored secret and anyone who can read where it is kept. An attacker who crosses it can sign in with credentials the vendor shipped or stored unprotected.
Questions to answer about your own systems
- Where does Cisco Secure Firewall Management Center (FMC) run in your systems, and at which version?
- Which of those instances can be reached from the internet or partner networks?
- What can it reach once compromised: which data stores, secrets and services?
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.