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-2026-76453 are related to improper neutralization issues that are grouped under the Common Weakness Enumeration (CWE) CWE-707.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-10-07T17:16:57.073Z",
  "pubdate": "2026-10-07T17:16:57.073Z",
  "executiveSummary": "Cisco NX-OS has been identified as containing multiple vulnerabilities categorized under CWE-707, specifically involving improper neutralization of inputs.\nThe vulnerability, tracked as CVE-2026-76453, originates from the software's failure to adequately sanitize or encode data before processing, which may lead to unauthorized data manipulation or system compromise.\nThese flaws affect the integrity of the NX-OS software suite and could be leveraged by an attacker to bypass security controls if input validation mechanisms are circumvented.\nThe risk implication is high, as improper neutralization often serves as a vector for injection-style attacks, potentially allowing for arbitrary command execution or unauthorized data modification within the network operating system environment.\nWhile exploitation requirements depend on specific access levels, the internal discovery indicates that the vulnerability is inherent to the handling of specific system functions within the NX-OS architecture.\nOrganizations relying on affected versions of Cisco NX-OS are advised to prioritize security hardening and follow established update protocols to mitigate the risks associated with these input neutralization flaws.",
  "technicalDetails": "CVE-2026-76453 pertains to a class of vulnerabilities defined by CWE-707: Improper Neutralization of Encoding. This issue manifests within the Cisco NX-OS software framework where input streams are processed without sufficient neutralization of control characters or escape sequences. The root cause is the failure of internal input-handling functions to verify that data conforms to expected schemas before passing it to system-level interpreters or execution contexts.\nThe vulnerability allows an attacker to manipulate input in a manner that bypasses existing security filters. By crafting specific payloads that exploit the lack of proper encoding neutralization, an adversary can force the system to interpret malicious data as legitimate control instructions or executable commands. This process effectively breaks the boundary between data and control plane operations within the NX-OS environment.\nThe exploitation flow typically begins with an attacker identifying a data ingestion point that consumes user-provided or network-transmitted input that is later used in an internal function call. If the input is not neutralized, the attacker can inject malformed data sequences. When the system performs a subsequent operation—such as a system call, configuration update, or data write—the improperly handled input causes the underlying function to execute unintended actions.\nBecause these vulnerabilities are categorized as improper neutralization, the post-exploitation impact may include unauthorized configuration modifications, the potential for local privilege escalation if the affected function runs with administrative rights, and the compromise of data integrity. The attack surface encompasses any interface or process that relies on the flawed sanitization routines defined in the affected Cisco NX-OS release.\nTechnical analysis of the vulnerability suggests that attackers do not require direct physical access but must be capable of reaching the input vectors processed by the vulnerable NX-OS components. Given that this is an internal discovery, the precise function names or specific code paths have not been publically disclosed to prevent weaponization, but the scope of the vulnerability implies broad impact across modules that handle external inputs. Without proper neutralization, the integrity of the Cisco NX-OS kernel or administrative shell could be compromised if an attacker successfully injects data that bypasses the neutralization logic."
}