CVE-2026-76471: Heap Overflow (CVSS 9.8)

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.

Is your site exposed to CVE-2026-76471?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

9.8

CRITICAL

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

EPSS — Exploit Prediction

0.0052

Probability of exploitation

0.43%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-122 CWE-122

References

Other References

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

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. It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2026-76471? +

CVE-2026-76471 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0052, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-76471? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-8997

vifm is vulnerable to a heap buffer overflow during the history merge process when saving the state file (vifminfo.json). This …

CVE-2026-8484

A heap buffer overflow vulnerability exists in the Jansi JNI "ioctl()" wrapper due to a lack of size verification for …

CVE-2026-6210

A type confusion vulnerability in Qt SVG allows an attacker to cause an application crash via a crafted SVG image. …

CVE-2026-2467

Heap-based Buffer Overflow vulnerability in RTI Connext Professional (Core Libraries) allows Overflow Variables and Tags.This issue affects Connext Professional: from …

CVE-2025-0633

Heap-based Buffer Overflow vulnerability in iniparser_dumpsection_ini() in iniparser allows attacker to read out of bound memory

CVE-2025-3512

There is a Heap-based Buffer Overflow vulnerability in QTextMarkdownImporter. This requires an incorrectly formatted markdown file to be passed to …

CVE-2026-76471