CVE-2026-20316mediumunder attackransomwareCWE-259

CVE-2026-20316: medium-severity vulnerability in Cisco Secure Firewall Management Center (FMC)

Cisco Secure Firewall Management Center Software Static Credential Vulnerability

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55Vexday Risk Score

Prioritize patching. It under exploitation confirmed by CISA and has an official Brazilian government alert.

ssvc Attendcvss 5.3epss 35%
from disclosure to weapon
Published on NVDJul 29
CISA KEVJul 29
Official alert in Brazil

Brazil's federal government published an alert, recommendation or bulletin that cites this vulnerability.

  • CTIR Gov · ALERTA 70/2026 · 25 Aug 2026Vulnerabilidade crítica que afeta o Secure Firewall Management Center (FMC)read on gov.br ↗
  • CISC Gov.br · 04 Aug 2026Boletim do CISC de Vulnerabilidaderead on gov.br ↗
Source: CTIR Gov (GSI) and CISC Gov.br, under the CC BY-ND 3.0 license.
Action required by CISAfederal deadline: 2026-08-01

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

In short

Cisco Secure Firewall Management Center has a built-in low-privileged account with a fixed password that anyone can use to log in remotely without authentication. An attacker can use this account to access sensitive information on the affected device.

Technical detail

A static credential vulnerability in the web interface of Cisco Secure Firewall Management Center allows unauthenticated remote access via a low-privileged account. The vulnerability is exploited through direct login using hardcoded credentials; impact is elevated when chained with other FMC vulnerabilities for privilege escalation. Attack surface is reduced if the management interface lacks internet exposure.

Summary generated and translated by AI from the official description.
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Affected products
Cisco · Cisco Secure Firewall Management Center (FMC)
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