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CVE-2026-76459

9.8, critical

Cisco NX-OS Software Out-of-Bounds Write Vulnerability

NVD (opens in a new tab) CVE.org (opens in a new tab)
CVSS
9.8, critical critical CVSS v3.1
EPSS, next 30 days
0.3% higher than 21.9% of scored CVEs
Exploitation
No public evidence
Published
7 Oct 202611 days ago

Description

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco NX-OS engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-76459 are related to out-of-bounds write issues that are grouped under the Common Weakness Enumeration (CWE) CWE-787.

Details

Vendor
Cisco
Product
Cisco NX-OS Software
Weakness
CWE-787 (opens in a new tab)
Status
Awaiting analysis
Updated
9 Oct 2026
Assigner
psirt@cisco.com

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

References 1

Advisories 1

The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.

Other Cisco CVEs

Every Cisco CVE we hold

Same vendor in what we hold, not a known link between the flaws.

  • CVE-2026-76519 Cisco Secure Email Gateway Relative Path Traversal Vulnerability KEV EPSS 2% 9.8, critical
  • CVE-2026-76504 Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability KEV EPSS 2% 9.8, critical
  • CVE-2026-76460 Cisco Identity Services Engine Incorrect Use of Privileged APIs Vulnerability KEV EPSS 14% 10, critical
  • CVE-2026-76461 Cisco Secure Email Gateway SQL Injection Vulnerability KEV EPSS 30% 9.8, critical
  • CVE-2026-20349 Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection Vulnerability KEV EPSS 1% 8.6, high
  • CVE-2026-20316 Cisco Secure Firewall Management Center Use of Hard-coded Password Vulnerability KEV EPSS 35% 5.3, medium
  • CVE-2026-20262 Cisco Catalyst SD-WAN Manager Directory or Path Traversal Vulnerability KEV EPSS 28% 6.5, medium
  • CVE-2026-20245 Cisco Catalyst SD-WAN Manager Improper Encoding or Escaping of Output Vulnerability KEV EPSS 25% 7.8, high

Beyond this page

Is CVE-2026-76459 in your network?

This page tells you how dangerous CVE-2026-76459 is out there. Whether it sits on one of your devices, only a scan of your own network can tell. That is what our systems do, every day, for the companies we protect.

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    Find it before attackers do

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  • EXYS7950 KONDRA

    Detect it if it's exploited

    Until the patch is applied, Kondra monitors your network, events and endpoints in real time. It keeps an inventory of the software installed on every endpoint, and its anomaly detection rules flag what an attacker does once inside.

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Check your exposure

Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 18 Oct 2026, not the live upstream state.