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-2026-76455 are related to improper access control issues that are grouped under the Common Weakness Enumeration (CWE) CWE-284.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-10-07T17:16:57.520Z",
  "pubdate": "2026-10-07T17:16:57.520Z",
  "executiveSummary": "Cisco NX-OS contains multiple vulnerabilities classified under CWE-284, specifically pertaining to improper access control. These security flaws, tracked collectively under CVE-2026-76455, were identified during an internal security assessment by the Cisco NX-OS engineering team.\nThe vulnerabilities expose the system to unauthorized access, potentially allowing an attacker to bypass established security policies. By exploiting these access control deficiencies, a threat actor could interact with system resources or execute operations that should be restricted to privileged users or authorized administrative contexts.\nThe impact of this vulnerability is significant, as improper access control can lead to unauthorized configuration changes, potential information disclosure, or the subversion of system integrity within the network environment.\nThe exploitation of these vulnerabilities generally requires the attacker to have network-level access to the Cisco NX-OS device, although specific entry points depend on the underlying implementation of the affected access control mechanisms. These flaws highlight a failure in the enforcement of authorization logic, necessitating timely security hardening to mitigate the risk of unauthorized system manipulation.",
  "technicalDetails": "The root cause of CVE-2026-76455 lies in flawed access control logic within the Cisco NX-OS architecture, specifically categorized under CWE-284 (Improper Access Control). This weakness implies that the security mechanisms intended to govern access to specific management interfaces, internal services, or administrative functions fail to adequately validate user identity or permission levels before granting access to sensitive operations.\nIn a typical attack flow, an attacker leverages the improper access control to bypass security checks that should be enforced by the NX-OS authorization framework. Since these vulnerabilities allow for unauthorized interaction, an attacker may attempt to invoke restricted commands or access system-level data without the necessary administrative credentials. The vulnerability resides within the software logic that mediates requests between the user interface and the backend processing components of the NX-OS operating system.\nThe exploitation process involves the transmission of malformed requests or the deliberate bypassing of expected authentication/authorization sequences directed at the target service. Because the access control mechanism is incorrectly implemented, it may grant a 'success' status to a request that fails to meet the expected policy requirements. The lack of strict verification allows for unauthorized state changes or data retrieval from the system.\nRegarding privilege and authentication requirements, these vulnerabilities frequently circumvent the necessity for elevated credentials. Depending on the specific vector identified within the internal audit, an unauthenticated or low-privileged user might reach the vulnerable component to perform actions intended for high-privileged administrators. Network exposure is primarily localized to the interface where the vulnerable service is listening; however, if the service is exposed to an untrusted segment, the attack surface is significantly increased.\nThe post-exploitation impact includes the potential for system compromise, unauthorized modification of device configurations, and potential disruption of critical network services managed by the affected Cisco NX-OS device. By successfully exploiting these access control failures, an attacker gains the capability to perform unauthorized actions that undermine the established security boundary of the product, potentially leading to persistent control or further exploitation within the networked infrastructure."
}