KEV Intelligence

Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2026-20131

Cisco Secure Firewall Management Center (FMC) Remote Code Execution

Cisco / Cisco Secure Firewall Management Center (FMC) · 7.0.0

View live feed Monitor via API
Severity
CVSS 10.0 · Critical
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
31.2%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-20131 is an unauthenticated vulnerability affecting Cisco Cisco Secure Firewall Management Center (FMC). A vulnerability in the web-based management interface of Cisco Secure Firewall Management Center (FMC)...

Is it exploited?

Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is confirmed.

Who is affected?

Cisco / Cisco Secure Firewall Management Center (FMC) 7.0.0.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Cisco Secure Firewall Management Center (FMC) Remote Code Execution

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.

Vendor Product Affected Status
Cisco Cisco Secure Firewall Management Center (FMC) 7.7.0 Affected
Cisco Cisco Secure Firewall Management Center (FMC) 7.4.2.2 Affected
Cisco Cisco Secure Firewall Management Center (FMC) 7.2.10 Affected
Cisco Cisco Secure Firewall Management Center (FMC) 7.6.1 Affected
Cisco Cisco Secure Firewall Management Center (FMC) 7.4.2.3 Affected
Cisco Cisco Secure Firewall Management Center (FMC) 7.0.8 Affected
Cisco Cisco Secure Firewall Management Center (FMC) 7.6.2 Affected
Cisco Cisco Secure Firewall Management Center (FMC) 7.7.10 Affected
Cisco Cisco Secure Firewall Management Center (FMC) 7.2.10.1 Affected
Cisco Cisco Secure Firewall Management Center (FMC) 7.0.8.1 Affected
Cisco Cisco Secure Firewall Management Center (FMC) 7.6.2.1 Affected
Cisco Cisco Secure Firewall Management Center (FMC) 7.2.10.2 Affected
Cisco Cisco Secure Firewall Management Center (FMC) 7.7.10.1 Affected
Cisco Cisco Secure Firewall Management Center (FMC) 7.4.2.4 Affected
Cisco Cisco Secure Firewall Management Center (FMC) 7.4.3 Affected
Cisco Cisco Secure Firewall Management Center (FMC) 7.7.11 Affected
Cisco Cisco Secure Firewall Management Center (FMC) 7.6.4 Affected
Cisco Cisco Secure Firewall Management Center (FMC) 10.0.0 Affected
Cisco Cisco Secure Firewall Management Center (FMC) 7.4.4 Affected
Cisco Cisco Secure Firewall Management Center (FMC) 7.4.5 Affected
Published
04 Mar 2026
Exploitation Reported
01 Jun 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

cisa edge malware

CVE References

  • CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2026-20131
  • cisco-sa-fmc-rce-NKhnULJh sec.cloudapps.cisco.com · CVE Record https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurity...

Exploitation evidence

Why KEV Intelligence marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CVE

Recorded 01 Jun 2026

Independent exploitation attestation added to the KEV Intelligence record.

Used in malware

CVE

Recorded 02 Jun 2026

Malware families have been linked to exploitation of this CVE.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.

Learn about Pro API access
Source Added
CVE First 2026-06-01 12:10 UTC
CISA 2026-06-02 14:02 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
0
User-Agents
0

Raw values available in Pro and Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

No detection artifacts or sensor request patterns are available for this CVE yet.

Check back as sensor telemetry and scanner integrations are updated.

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

10.0 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

EPSS

31.2%

Weaknesses

Deserialization of Untrusted Data CWE-502

Timeline

From disclosure to observed exploitation

  1. First public exploitation report

    Exploit observed in malware

  2. Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  3. Added to KEV Intelligence KEV Feed

    High-confidence, third-party attested exploitation

  4. CVE published

    Vulnerability disclosed publicly

  5. CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

View Pro pricing Read API docs
  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-20131

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2026-20131",
  "confidence": "Confirmed",
  "cvss_score": 10.0,
  "cvss_estimated": false,
  "epss_score": 0.31231,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}

Early warning alerts

Get alerts on high-impact exploitation

Receive curator-selected alerts when exploitation activity warrants attention. Each alert includes the evidence and context needed to decide what requires attention now.

Occasional high-impact alerts. Unsubscribe anytime. See our Privacy Policy.