Threat Intelligence / CVE / CVE-2026-20265

CVE-2026-20265 — Cisco Secure Firewall Management Center (FMC) 7.2.0-7.6.2

CISA KEV

CVSS v3.1 9.8 (CRITICAL) · Priority 9/10

As of 2026-09-13, CVE-2026-20265 is a CRITICAL-severity vulnerability in Cisco Secure Firewall Management Center (FMC) 7.2.0-7.6.2, CVSS v3.1 9.8. It is listed in the CISA Known Exploited Vulnerabilities catalog. Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-20265, most recently “Interlock Ransomware Exploits Cisco FMC Zero-Day (CVE-2026-20265) Amid March 2026 CVE Surge”.

Last updated: 2026-09-13

What is CVE-2026-20265?

Unauthenticated remote code execution vulnerability in Cisco Secure Firewall Management Center (FMC) web management interface. The flaw resides in the HTTPS administration endpoint and stems from improper input validation inside the CertEnrollServlet Java servlet, where attacker-controlled XML parameters are deserialized without validation, yielding arbitrary OS command execution as the tomcat user. FMC versions 7.2.0 through 7.6.2 are affected. Actively exploited by Interlock ransomware group using AdaptixC2 framework. CISA KEV added 2026-04-10 with remediation deadline 2026-04-24.

The record classifies CVE-2026-20265 under weakness classes CWE-502, CWE-78, CWE-306. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below.

Severity and exploitation probability

CVSS v3.1 base score: 9.8 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA KEV: Listed
Threadlinqs priority: 9/10 — CISA KEV-listed, which Threadlinqs floors at 9

Is CVE-2026-20265 being exploited?

CISA added CVE-2026-20265 to the Known Exploited Vulnerabilities catalog, which means the agency holds evidence of exploitation in the wild. It currently carries a trending score of 15 in the Threadlinqs vulnerability feed.

Affected products and versions

(vendor unspecified): Cisco Secure Firewall Management Center (FMC) 7.2.0-7.6.2

How to fix CVE-2026-20265

No vendor patch reference has been recorded for CVE-2026-20265 in the tracked sources. Watch the CNA record and the vendor advisory channel for a fix, and treat the products listed above as exposed until the vendor states otherwise.

Threat activity tracking CVE-2026-20265

1 tracked threat in the Threadlinqs corpus references CVE-2026-20265, either in the campaign’s CVE list or as an indicator on the campaign record.

Interlock Ransomware Exploits Cisco FMC Zero-Day (CVE-2026-20265) Amid March 2026 CVE Surge — CRITICAL · 2026-04-13

Sources

Seeded from threat-derived and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.

No external references are recorded on this row.

Full detection coverage & IOCs for threats exploiting CVE-2026-20265 are available via the Threadlinqs MCP server (Purple tier). View plans →

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