CVE-2026-20131
Cisco Secure Firewall Management Center Software Remote Code Execution Vulnerability
- Published
- Updated
- Reserved
- Assigned by
- cisco
Description
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.
Exploited in the wild
CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as Cisco Secure Firewall Management Center (FMC) Software and Cisco Security Cloud Control (SCC) Firewall Management Deserialization of Untrusted Data Vulnerability.
- Added
- 19 Mar 2026
- Fix due (US federal)
- 22 Mar 2026
- Used by ransomware
- Known
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| ciscoCNA (assigner) | 3.1 | Critical10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
| NVDNVD · Analyzed | 3.1 | Critical10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 44.4% · top 1.2% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: active · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 10.0.
Weakness
Affected products
Cisco · Cisco Secure Firewall Management Center (FMC)
- affected 7.0.0
- affected 7.0.0.1
- affected 7.0.1
- affected 7.1.0
- affected 6.4.0.13
- affected 7.0.1.1
- affected 6.4.0.14
- affected 7.1.0.1
- affected 7.0.2
- affected 6.4.0.15
- affected 7.2.0
- affected 7.0.2.1
- affected 7.0.3
- affected 7.1.0.2
- affected 7.2.0.1
- affected 7.0.4
- affected 7.2.1
- affected 7.0.5
- affected 6.4.0.16
- affected 7.3.0
- affected 7.2.2
- affected 7.3.1
- affected 7.2.3
- affected 7.1.0.3
- affected 7.2.3.1
- affected 7.2.4
- affected 7.0.6
- affected 7.2.4.1
- affected 7.2.5
- affected 7.3.1.1
- affected 7.4.0
- affected 6.4.0.17
- affected 7.0.6.1
- affected 7.2.5.1
- affected 7.4.1
- affected 7.2.6
- affected 7.4.1.1
- affected 7.0.6.2
- affected 6.4.0.18
- affected 7.2.7
- and 30 more
What to do
Exploitation: In March 2026, the Cisco Product Security Incident Response Team (PSIRT) became aware of attempted exploitation of this vulnerability. Cisco continues to strongly recommend that customers upgrade to a fixed software release to remediate this vulnerability.
References (3)
- cisco-sa-fmc-rce-NKhnULJh (opens in a new tab)
- https://aws.amazon.com/blogs/security/amazon-threat-intelligence-teams-identify-interlock-ransomware-campaign-targeting-enterprise-firewalls/ (opens in a new tab)third-party-advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20131 (opens in a new tab)government-resource
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- CISA KEV catalog (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-20131)Record last updated .