CVE-2026-20131
Confirmed PUBLISHEDCisco Secure Firewall Management Center Software Remote Code Execution Vulnerability
1 day faster than CISA KEV
Recommended Action
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
At a Glance
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.
- CVE Published
- Mar 04, 2026
- Exploitation Reported
- Jun 01, 2026
- CVSS
- 10.0 Critical
- EPSS
- 27.6%
Affected Versions
70 version rows · page 2 of 3
| Vendor | Product | Version | Status |
|---|---|---|---|
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.2.4 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.0.6 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.2.4.1 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.2.5 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.3.1.1 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.4.0 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
6.4.0.17 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.0.6.1 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.2.5.1 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.4.1 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.2.6 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.4.1.1 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.0.6.2 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
6.4.0.18 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.2.7 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.2.5.2 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.3.1.2 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.2.8 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.6.0 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.4.2 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.2.8.1 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.0.6.3 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.4.2.1 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.2.9 |
Affected |
| Cisco |
Cisco Secure Firewall Management Center (FMC)
|
7.0.7 |
Affected |
CVE References
- cisco-sa-fmc-rce-NKhnULJh sec.cloudapps.cisco.com · CVE Record https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurity...
Recommended Actions
- Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
- Check enrichment artifacts for scanner coverage and available PoCs before rolling remediation validation.
- Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CVE First | 2026-06-01 12:10 UTC |
| CISA | 2026-06-02 14:02 UTC |
No detection artifacts or sensor request patterns are available for this CVE yet.
Check back as sensor telemetry and scanner integrations are updated.
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
KEVIntel does not currently have a virtual patch for this CVE. When available, KEVIntel virtual patches ship as deployable ModSecurity, Cloudflare, and AWS WAF rules.
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users.
CVSS Scores
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Exploitation Status
Exploited in the wild
Recorded 2026-06-01 12:10:30 UTC · CVE
Used in malware
Recorded 2026-06-02 14:02:44 UTC · CVE
Proof of concept available
Recorded 2026-03-06 07:06:56 UTC · GitHub
Weaknesses (CWE)
-
Deserialization of Untrusted Data
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
github · Created 2026-03-11 01:30:51 UTC · 3 stars
github · Created 2026-03-06 07:06:56 UTC · 0 stars
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
14:02 UTC about 1 month ago14:02 UTC · about 1 month ago
First public exploitation report
Exploit observed in malware
-
14:02 UTC about 1 month ago14:02 UTC · about 1 month ago
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
12:10 UTC about 2 months ago12:10 UTC · about 2 months ago
Added to KEVIntel KEV Feed
High-confidence, third-party attested exploitation
-
07:06 UTC 4 months ago07:06 UTC · 4 months ago
Public PoC available
Public proof-of-concept code published
-
17:17 UTC 4 months ago17:17 UTC · 4 months ago
CVE published
Vulnerability disclosed publicly
-
11:59 UTC 9 months ago11:59 UTC · 9 months ago
CVE ID reserved
Identifier reserved by the CNA
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v2/pro/kevs/CVE-2026-20131
{
"cve_id": "CVE-2026-20131",
"title": "Cisco Secure Firewall Management Center Software Remote Code Execution Vulner...",
"affected_vendor": "Cisco",
"affected_product": "Cisco Secure Firewall Management Center (FMC)",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "Confirmed",
"cvss_score": 10.0,
"epss_score": 0.27551,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}