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Used in attacks· fix by 2026-08-01Not scored yetUsed by ransomware gangs

Cisco Secure Firewall Management Center (FMC)

CVE-2026-20316

Cisco Secure Firewall Management Center (FMC) formerly known as Firepower Management Center contains a use of hard-coded password vulnerability that 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.

What this means for your business

  • It affects Cisco Secure Firewall Management Center (FMC). It matters if your company, or a supplier that handles your data, runs it.
  • Attackers are already using it. CISA added it to its list of flaws used in real attacks on 29 July 2026.
  • Ransomware gangs are known to have used it.
  • FIRST's prediction model gives it a 11% chance of attack attempts being seen in the next 30 days, ranking above 95% of all known flaws.

What to do

  1. 1Check whether your company or your suppliers run Cisco Secure Firewall Management Center (FMC).
  2. 2If you do, follow CISA's required action below. No patch reference has been published yet.
  3. 3Treat it as urgent. US federal agencies must fix it by 1 August 2026. That deadline does not apply to private companies, but it shows how seriously CISA takes it.
  4. 4Because attackers have used it, check the affected systems for signs of a break-in, not only for the update.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

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Required action

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.

CISA’s wording, unedited. The notes it mentions are in CISA’s catalogue entry.

Scoring

CVSS
Not yet scored

Dates

Published
2026-07-29
Added to KEV
2026-07-29
Remediation due
2026-08-01
Sources
CISA KEV

Coverage