CVE-2026-20316 - PatchNow

📋 Vulnerability Details

Data Source: CIRCL

Confidence: HIGH

Exploitation Method: DIRECT_NETWORK

CVE Published: 2026-07-29

Added to CISA KEV: 2026-07-29 0 DAY BETWEEN CVE AND KEV

🎯 Recommendations:

CRITICAL: Check for indicators of compromise - this vulnerability is in CISA KEV indicating active exploitation in the wild. Review authentication logs, especially for logins using the low-privileged static account named in Cisco's advisory, and verify system integrity
Immediately apply Cisco's patched software releases per the referenced security advisory (cisco-sa-fmc-static-cred-BET3Cjh)
Restrict FMC web management interface access to trusted internal networks only; disable any internet-facing exposure of the management interface
Monitor for unusual login activity from the static low-privileged account and correlate with any subsequent privilege escalation attempts using other FMC CVEs
Patch priority: HIGH — despite a moderate CVSS score, active exploitation and KEV listing warrant urgent remediation

🔍 Web Intelligence (Kagi · 2026-09-14)

Summary

CVE-2026-20316 is a critical vulnerability identified in the web interface of Cisco Secure Firewall Management Center (FMC) Software, caused by the inclusion of hard-coded, static user credentials for a low-privileged account. This flaw allows an unauthenticated, remote attacker to leverage these credentials to gain unauthorized access to the affected device. It matters significantly because it provides an entry point for attackers to access sensitive data and potentially conduct further malicious activities within the impacted environment, leading to its inclusion in the CISA Known Exploited Vulnerabilities (KEV) catalog.

Exploitation

Active Exploitation: The vulnerability has been confirmed as being actively exploited in the wild, having been utilized as a zero-day attack vector .
Threat Actors: While active exploitation is documented, specific named threat actors or ransomware campaigns have not been publicly attributed to this vulnerability as of the reporting date.
Proof-of-Concept: Publicly available information confirms the mechanism of the vulnerability relies on the use of static credentials, which facilitates unauthorized access without requiring complex exploit code.
Attack Prerequisites: This is a remote, unauthenticated attack; no user interaction is required for exploitation, and the threat exists over the network .

Affected Products & Patches

Affected Products: Cisco Secure Firewall Management Center (FMC) Software is the primary component identified as vulnerable to this static credential flaw.
Patch Availability: Cisco has released security advisories regarding this issue. Administrators are urged to consult the official Cisco Security Advisory for specific affected software versions and to apply the necessary patches or upgrades as recommended by the vendor .
Mitigations/Workarounds: Organizations should restrict access to the FMC web management interface to trusted networks only and monitor logs for unusual authentication patterns associated with low-privileged accounts until the official patch is applied.

Impact

Access/Capabilities: Successful exploitation grants an unauthenticated attacker the ability to log in to the FMC device using the static, low-privileged account, providing them with unauthorized access to sensitive data stored within or managed by the system .
Business Risk: For internet-facing deployments, the risk is severe, as the appliance becomes directly reachable by remote attackers who can bypass authentication to compromise the management layer of the firewall infrastructure, potentially leading to broader network infiltration or data exfiltration.