Riskcovery

CVE-2026-20242

Cisco Secure Firewall Management Center Software Java Deserialization Remote Code Execution Vulnerability

State
Published
Severity
9.8 Critical
Published
Sep 16, 2026
Updated
Sep 18, 2026
Reserved
Oct 8, 2025

Read the record on cve.org

Description

A vulnerability in the External Database Access feature of Cisco Secure Firewall Management Center (FMC) Software could allow an unauthenticated, remote attacker to execute arbitrary commands as root on an affected device.

This vulnerability is due to insecure deserialization of a user-supplied Java byte stream from a host that is configured in the external database access list. An attacker could exploit this vulnerability by sending a crafted, serialized Java byte stream to a specific TCP port of an affected device. A successful exploit could allow the attacker to execute arbitrary commands on the device and elevate privileges to root. Notes:

This vulnerability can be exploited only by an attacker who has control of a host in the external database access list. If the FMC management interface does not have public internet access, the attack surface that is associated with this vulnerability is reduced.

Scores

CVSSScoreVectorSource
3.19.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hcisco

Weaknesses

  • CWE-502 Deserialization of Untrusted Data

Affected Products

ProductVersions
Cisco Secure Firewall Management Center (FMC)Cisco
  • 7.0.0Affected
  • 7.0.0.1Affected
  • 7.0.1Affected
  • 7.0.1.1Affected
  • 7.0.2Affected
  • 7.2.0Affected
  • 7.0.2.1Affected
  • 7.0.3Affected
  • 7.2.0.1Affected
  • 7.0.4Affected
  • 7.2.1Affected
  • 7.0.5Affected
  • 7.3.0Affected
  • 7.2.2Affected
  • 7.3.1Affected
  • 7.2.3Affected
  • 7.2.3.1Affected
  • 7.2.4Affected
  • 7.0.6Affected
  • 7.2.4.1Affected
  • 7.2.5Affected
  • 7.3.1.1Affected
  • 7.4.0Affected
  • 7.0.6.1Affected
  • 7.2.5.1Affected
  • and 43 more versions

References

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