Vulnerability · Published Oct 7, 2026 · Assigned by cisco
CVE-2026-76459Cisco NX-OS Software Security Hardening Release: October 2026 - Out-of-bounds Write Vulnerabilities
Critical 9.8
In plain English
A critical-severity out-of-bounds write in Cisco NX-OS Software from Cisco. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities).
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco NX-OS Software | 8.2(5)7.3(5)D1(1)8.4(2)8.4(3)9.2(3)8.2(1)7.3(1)D1(1)9.2(2v) |
| Cisco | Cisco NX-OS System Software in ACI Mode | 15.2(1g)15.2(2e)15.2(2f)15.2(2g)15.2(2h)15.2(3f)15.2(3e)15.2(3g) |
| Cisco | Cisco Unified Computing System (Managed) | 4.0(1a)4.1(1d)4.0(4f)4.0(4c)4.0(2b)4.1(2a)4.0(4a)4.0(4e) |
Weakness: CWE-787 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H