Critical [CVE-2026-20131] Cisco Secure Firewall Management Center Software Remote Code Execution Vulnerability
This critical-severity Cisco advisory covers CVE-2026-20131 affecting Cisco Secure Firewall Management Center (FMC).
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Summary
A vulnerability in the web-based management interface of Cisco Secure Firewall Management Center (FMC) Software could allow an unauthenticated, remote attacker to execute arbitrary Java code as root on an affected device. This vulnerability is due to insecure deserialization of a user-supplied Java byte stream.
An attacker could exploit this vulnerability by sending a crafted serialized Java object to the web-based management interface of an affected device. A successful exploit could allow the attacker to execute arbitrary code on the device and elevate privileges to root.
Note: If the FMC…
CISA Known Exploited Vulnerability
- Listed:
- Mar 19, 2026 · federal remediation due Mar 22, 2026
- Required action:
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- Ransomware use:
- Known
KEV is a prioritization signal from CISA — remediation detail still comes from the vendor advisory.
- Scope: This vulnerability affects Cisco Secure FMC Software and Cisco Security Cloud Control (SCC) Firewall Management, regardless of device configuration.
Official advisory · high-confidence parse· fetched 2 months ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · high-confidence parse· fetched 2 months ago·verify at source
Mitigation checklist
- There are no workarounds that address this vulnerability.
Official advisory · high-confidence parse· fetched 2 months ago·verify at source
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