Cisco Secure Firewall Management Center (FMC) Software and Cisco Security Cloud Control (SCC) Firewall Management Deserialization of Untrusted Data Vulnerability
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…
Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.
Exploitation probability EPSS · FIRST
Exploitation signals 5 / 5
- KEV catalog (CISA)19 Mar 2026
- Exploited in EUVD (ENISA)19 Mar 2026
- Used by ransomwareyes
- EPSS above 10 %44.4%
- No account, over the networkyes
What to do
Fix
Apply the vendor’s fix as soon as it is available.
CISA guidance: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Meanwhile
Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.
Manufacturers (CRA)
Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained
Description ENISA EUVD
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 management interface does not have public internet access, the attack surface that is associated with this vulnerability is reduced.
Affected products
- 7.0.6.2
- 7.6.2
- 7.7.11
- 7.2.10
- 7.4.4
- 7.4.2
- 7.2.9
- 6.4.0.13
- 7.2.8
- 7.0.5
- 7.0.8.1
- 7.0.3
Open source packages OSV
Affected libraries according to OSV, with fixed versions.
Timeline
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Published
-
Exploitation reported (ENISA)
-
Added to the KEV catalog
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CISA remediation due date
-
EPSS peak: 44.4%
References
Other exploited vulnerabilities from the same vendor
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- CVE-2026-76504Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability7.5 · Actively exploited
- CVE-2026-76460Cisco Identity Services Engine Incorrect Use of Privileged APIs Vulnerability8.7 · Actively exploited
- CVE-2026-76461Cisco Secure Email Gateway SQL Injection Vulnerability7.2 · Actively exploited
- CVE-2026-20079Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability9.1 · Actively exploited