CVE-2026-76471: Cisco NX-OS Software Heap Buffer Overflow

Description

A vulnerability in the NX-API feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to execute arbitrary code with root privileges or cause a denial of service (DoS) condition on an affected device.  The vulnerability is due to insufficient input validation of data that is sent to the NX-API. An attacker could exploit this vulnerability by sending a crafted HTTP request to the NX-API of an affected device. A successful exploit could allow the attacker to execute arbitrary code with root privileges and could cause process crashes, which could result in a reload of the device and a DoS condition.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

0.52%

42.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-122

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Cisco	Cisco NX-OS Software	9.2(3); 9.2(2v); 9.2(1); 9.2(2t); 9.2(3y); 9.3(2); 9.2(4); 9.3(1); 9.3(1z); 9.2(2); 9.3(3); 9.3(4); 9.3(5); 9.3(6); 9.3(5w); 9.3(7); 9.3(7k); 9.3(7a); 9.3(8); 9.3(9); 9.3(10); 10.3(1); 10.3(2); 9.3(11); 10.3(3); 9.3(12); 10.4(1); 10.3(99w); 10.3(3w); 10.3(99x); 10.3(3o); 10.3(4); 10.3(3p); 10.3(4a); 10.4(2); 10.3(3q); 9.3(13); 10.3(5); 10.4(3); 10.3(3x); 10.3(4g); 10.5(1); 10.3(3r); 10.3(6); 9.3(14); 10.4(4); 10.3(4h); 10.5(2); 10.3(7); 10.4(5); 10.5(3); 9.3(15); 10.4(4g); 10.5(4); 10.6(1); 10.5(3t); 10.3(8); 10.4(6); 10.5(3s); 10.5(3e); 10.5(3o); 9.3(16); 10.6(1s); 10.6(2); 10.5(3p); 10.3(9); 10.6(2s); 10.6(3); 10.4(7); 10.5(5); 9.3(17); 10.6(2n); 10.6(3s)
Cisco	Cisco Unified Computing System (Managed)	4.0(1a); 4.1(1d); 4.0(4f); 4.0(4a); 4.0(4e); 4.0(4c); 4.0(4h); 4.1(1c); 4.0(2a); 4.1(1e); 4.1(2a); 4.0(2b); 4.0(1b); 4.0(4d); 4.0(2e); 4.1(1a); 4.0(4g); 4.0(1c); 4.0(1d); 4.0(4b); 4.0(4i); 4.0(2d); 4.1(1b); 4.1(2b); 4.0(4k); 4.1(3a); 4.1(3b); 4.1(2c); 4.0(4l); 4.1(4a); 4.1(3c); 4.1(3d); 4.2(1c); 4.2(1d); 4.0(4m); 4.1(3e); 4.2(1f); 4.1(3f); 4.2(1i); 4.1(3h); 4.2(1k); 4.2(1l); 4.0(4n); 4.2(1m); 4.1(3i); 4.2(2a); 4.2(1n); 4.1(3j); 4.2(2c); 4.2(2d); 4.2(3b); 4.1(3k); 4.0(4o); 4.2(2e); 4.2(3d); 4.2(3e); 4.2(3g); 4.1(3l); 4.3(2b); 4.2(3h); 4.2(3i); 4.3(2c); 4.1(3m); 4.3(2e); 4.3(3a); 4.2(3j); 4.3(3c); 4.3(4a); 4.2(3k); 4.3(4b); 4.3(4c); 4.2(3l); 4.3(4d); 4.3(2f); 4.2(3m); 4.3(5a); 4.3(4e); 4.1(3n); 4.3(4f); 4.2(3n); 4.3(5c); 4.2(3o); 4.3(5d); 4.3(6a); 4.3(6b); 4.3(5e); 4.3(6c); 4.2(3p); 4.3(6d); 4.3(6e); 4.3(6f); 4.2(3r); 4.3(6g); 4.3(6h); 4.2(3s); 4.3(6i)

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-napi-rce-r2shwu2j

Timeline

Published: Oct 7, 2026
Last Modified: Oct 8, 2026
Status: Awaiting Analysis

Frequently Asked Questions

What is CVE-2026-76471?

A vulnerability in the NX-API feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to execute arbitrary code with root privileges or cause a denial of service (DoS) condition on an affected device.  The vulnerability is due to insufficient input validation of data that is sent to the NX-API. An attacker could exploit this vulnerability by sending a crafted HTTP request to the NX-API of an affected device. A successful exploit could allow the attacker to execute arbitrary code with root privileges and could cause process crashes, which could result in a reload of the device and a DoS condition.

How severe is CVE-2026-76471?

CVE-2026-76471 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.52% probability of exploitation in the next 30 days.

How do I fix CVE-2026-76471?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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