NX-OS OOB Write (CWE-787) Vulnerability
CVE-2026-76459 Published on October 7, 2026
Cisco NX-OS Software Security Hardening Release: October 2026 - Out-of-bounds Write Vulnerabilities
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.
Vulnerability Analysis
CVE-2026-76459 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be critical as this vulnerability has a high impact to the confidentiality, integrity and availability of this component.
Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH
Weakness Type
What is a Memory Corruption Vulnerability?
The software writes data past the end, or before the beginning, of the intended buffer. Typically, this can result in corruption of data, a crash, or code execution. The software may modify an index or perform pointer arithmetic that references a memory location that is outside of the boundaries of the buffer. A subsequent write operation then produces undefined or unexpected results.
CVE-2026-76459 has been classified to as a Memory Corruption vulnerability or weakness.
Products Associated with CVE-2026-76459
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Affected Versions
Cisco NX-OS Software:- Version 8.2(5) is affected.
- Version 7.3(5)D1(1) is affected.
- Version 8.4(2) is affected.
- Version 8.4(3) is affected.
- Version 9.2(3) is affected.
- Version 8.2(1) is affected.
- Version 7.3(1)D1(1) is affected.
- Version 9.2(2v) is affected.
- Version 7.3(0)D1(1) is affected.
- Version 7.3(4)D1(1) is affected.
- Version 9.2(1) is affected.
- Version 9.2(2t) is affected.
- Version 9.2(3y) is affected.
- Version 9.3(2) is affected.
- Version 7.3(1)DY(1) is affected.
- Version 8.1(1) is affected.
- Version 8.2(2) is affected.
- Version 8.3(2) is affected.
- Version 7.3(2)D1(3a) is affected.
- Version 9.2(4) is affected.
- Version 8.1(2) is affected.
- Version 7.3(3)D1(1) is affected.
- Version 8.2(3) is affected.
- Version 8.3(1) is affected.
- Version 8.4(1) is affected.
- Version 8.1(1b) is affected.
- Version 7.3(0)DX(1) is affected.
- Version 7.3(2)D1(1) is affected.
- Version 9.3(1) is affected.
- Version 7.3(2)D1(2) is affected.
- Version 8.2(4) is affected.
- Version 7.3(0)DY(1) is affected.
- Version 9.3(1z) is affected.
- Version 9.2(2) is affected.
- Version 8.1(2a) is affected.
- Version 7.3(2)D1(3) is affected.
- Version 8.1(1a) is affected.
- Version 8.4(1a) is affected.
- Version 9.3(3) is affected.
- Version 7.3(2)D1(1d) is affected.
- Version 9.3(4) is affected.
- Version 7.3(6)D1(1) is affected.
- Version 8.2(6) is affected.
- Version 9.3(5) is affected.
- Version 8.4(2a) is affected.
- Version 8.4(2b) is affected.
- Version 8.5(1) is affected.
- Version 9.3(6) is affected.
- Version 8.4(4) is affected.
- Version 7.3(7)D1(1) is affected.
- Version 8.4(2c) is affected.
- Version 9.3(5w) is affected.
- Version 8.2(7) is affected.
- Version 9.3(7) is affected.
- Version 9.3(7k) is affected.
- Version 7.3(8)D1(1) is affected.
- Version 9.3(7a) is affected.
- Version 8.2(7a) is affected.
- Version 9.3(8) is affected.
- Version 8.4(4a) is affected.
- Version 8.4(2d) is affected.
- Version 8.4(5) is affected.
- Version 8.2(8) is affected.
- Version 9.3(9) is affected.
- Version 7.3(9)D1(1) is affected.
- Version 8.4(6) is affected.
- Version 8.4(2e) is affected.
- Version 9.3(10) is affected.
- Version 9.2(1a) is affected.
- Version 8.2(9) is affected.
- Version 10.3(1) is affected.
- Version 8.4(7) is affected.
- Version 10.3(2) is affected.
- Version 8.4(6a) is affected.
- Version 9.3(11) is affected.
- Version 10.3(3) is affected.
- Version 9.4(1) is affected.
- Version 9.3(2a) is affected.
- Version 8.4(2f) is affected.
- Version 8.2(10) is affected.
- Version 9.3(12) is affected.
- Version 10.4(1) is affected.
- Version 8.4(8) is affected.
- Version 10.3(99w) is affected.
- Version 10.3(3w) is affected.
- Version 10.3(99x) is affected.
- Version 10.3(3o) is affected.
- Version 8.4(9) is affected.
- Version 10.3(4) is affected.
- Version 10.3(3p) is affected.
- Version 10.3(4a) is affected.
- Version 9.4(1a) is affected.
- Version 10.4(2) is affected.
- Version 10.3(3q) is affected.
- Version 9.3(13) is affected.
- Version 8.2(11) is affected.
- Version 9.4(2) is affected.
- Version 10.3(5) is affected.
- Version 10.4(3) is affected.
- Version 10.3(3x) is affected.
- Version 10.3(4g) is affected.
- Version 10.5(1) is affected.
- Version 8.4(10) is affected.
- Version 9.4(2a) is affected.
- Version 10.3(3r) is affected.
- Version 10.3(6) is affected.
- Version 9.3(14) is affected.
- Version 10.4(4) is affected.
- Version 10.3(4h) is affected.
- Version 10.5(2) is affected.
- Version 10.5(1j) is affected.
- Version 8.4(11) is affected.
- Version 9.4(3) is affected.
- Version 10.3(7) is affected.
- Version 10.4(5) is affected.
- Version 10.5(3) is affected.
- Version 9.3(15) is affected.
- Version 9.4(3a) is affected.
- Version 10.4(4g) is affected.
- Version 10.5(4) is affected.
- Version 9.4(3b) is affected.
- Version 8.4(12) is affected.
- Version 10.6(1) is affected.
- Version 10.5(3t) is affected.
- Version 10.3(8) is affected.
- Version 10.4(6) is affected.
- Version 10.5(3s) is affected.
- Version 10.5(3e) is affected.
- Version 9.4(4) is affected.
- Version 10.5(3o) is affected.
- Version 9.3(16) is affected.
- Version 10.6(1s) is affected.
- Version 10.6(2) is affected.
- Version 10.5(3p) is affected.
- Version 9.4(5) is affected.
- Version 10.3(9) is affected.
- Version 10.6(2s) is affected.
- Version 8.4(13) is affected.
- Version 10.6(3) is affected.
- Version 10.4(7) is affected.
- Version 10.5(5) is affected.
- Version 9.3(17) is affected.
- Version 10.6(2n) is affected.
- Version 10.6(3q) is affected.
- Version 10.6(3o) is affected.
- Version 10.6(3s) is affected.
- Version 15.2(1g) is affected.
- Version 15.2(2e) is affected.
- Version 15.2(2f) is affected.
- Version 15.2(2g) is affected.
- Version 15.2(2h) is affected.
- Version 15.2(3f) is affected.
- Version 15.2(3e) is affected.
- Version 15.2(3g) is affected.
- Version 15.2(4d) is affected.
- Version 15.2(4e) is affected.
- Version 15.2(5c) is affected.
- Version 15.2(5d) is affected.
- Version 16.0(1g) is affected.
- Version 15.2(5e) is affected.
- Version 15.2(4f) is affected.
- Version 15.2(6e) is affected.
- Version 15.2(6h) is affected.
- Version 16.0(1j) is affected.
- Version 15.2(6g) is affected.
- Version 15.2(7f) is affected.
- Version 15.2(7g) is affected.
- Version 16.0(2h) is affected.
- Version 15.2(8d) is affected.
- Version 16.0(2j) is affected.
- Version 15.2(8e) is affected.
- Version 16.0(3d) is affected.
- Version 16.0(3e) is affected.
- Version 15.2(8f) is affected.
- Version 15.2(8g) is affected.
- Version 15.3(1d) is affected.
- Version 15.2(8h) is affected.
- Version 16.0(4c) is affected.
- Version 15.3(2a) is affected.
- Version 15.2(8i) is affected.
- Version 16.0(5h) is affected.
- Version 15.3(2b) is affected.
- Version 16.0(3g) is affected.
- Version 16.0(5j) is affected.
- Version 15.3(2c) is affected.
- Version 16.0(6c) is affected.
- Version 15.3(2d) is affected.
- Version 16.1(1f) is affected.
- Version 16.0(7e) is affected.
- Version 16.0(8e) is affected.
- Version 15.3(2e) is affected.
- Version 16.0(8f) is affected.
- Version 16.1(2f) is affected.
- Version 16.1(2g) is affected.
- Version 15.3(2f) is affected.
- Version 16.0(9c) is affected.
- Version 16.1(3f) is affected.
- Version 16.0(9d) is affected.
- Version 16.0(6h) is affected.
- Version 16.0(8h) is affected.
- Version 16.1(3g) is affected.
- Version 16.0(9e) is affected.
- Version 16.1(4h) is affected.
- Version 16.1(5e) is affected.
- Version 16.2(1g) is affected.
- Version 16.0(9f) is affected.
- Version 16.2(2e) is affected.
- Version 4.0(1a) is affected.
- Version 4.1(1d) is affected.
- Version 4.0(4f) is affected.
- Version 4.0(4c) is affected.
- Version 4.0(2b) is affected.
- Version 4.1(2a) is affected.
- Version 4.0(4a) is affected.
- Version 4.0(4e) is affected.
- Version 4.0(4h) is affected.
- Version 4.0(2a) is affected.
- Version 4.1(1c) is affected.
- Version 4.0(1b) is affected.
- Version 4.1(1e) is affected.
- Version 4.0(4d) is affected.
- Version 4.0(4b) is affected.
- Version 4.0(2e) is affected.
- Version 4.1(1a) is affected.
- Version 4.0(4g) is affected.
- Version 4.0(1d) is affected.
- Version 4.0(1c) is affected.
- Version 4.0(4i) is affected.
- Version 4.0(2d) is affected.
- Version 4.1(1b) is affected.
- Version 4.1(2b) is affected.
- Version 4.0(4k) is affected.
- Version 4.1(3a) is affected.
- Version 4.1(3b) is affected.
- Version 4.1(2c) is affected.
- Version 4.0(4l) is affected.
- Version 4.1(4a) is affected.
- Version 4.1(3c) is affected.
- Version 4.1(3d) is affected.
- Version 4.2(1c) is affected.
- Version 4.2(1d) is affected.
- Version 4.0(4m) is affected.
- Version 4.1(3e) is affected.
- Version 4.2(1f) is affected.
- Version 4.1(3f) is affected.
- Version 4.2(1i) is affected.
- Version 4.1(3h) is affected.
- Version 4.2(1k) is affected.
- Version 4.2(1l) is affected.
- Version 4.0(4n) is affected.
- Version 4.2(1m) is affected.
- Version 4.1(3i) is affected.
- Version 4.2(2a) is affected.
- Version 4.2(1n) is affected.
- Version 4.1(3j) is affected.
- Version 4.2(2c) is affected.
- Version 4.2(2d) is affected.
- Version 4.2(3b) is affected.
- Version 4.1(3k) is affected.
- Version 4.0(4o) is affected.
- Version 4.2(2e) is affected.
- Version 4.2(3d) is affected.
- Version 4.2(3e) is affected.
- Version 4.2(3g) is affected.
- Version 4.1(3l) is affected.
- Version 4.3(2b) is affected.
- Version 4.2(3h) is affected.
- Version 4.2(3i) is affected.
- Version 4.3(2c) is affected.
- Version 4.1(3m) is affected.
- Version 4.3(2e) is affected.
- Version 4.3(3a) is affected.
- Version 4.2(3j) is affected.
- Version 4.3(3c) is affected.
- Version 4.3(4a) is affected.
- Version 4.2(3k) is affected.
- Version 4.3(4b) is affected.
- Version 4.3(4c) is affected.
- Version 4.2(3l) is affected.
- Version 4.3(4d) is affected.
- Version 4.3(2f) is affected.
- Version 4.2(3m) is affected.
- Version 4.3(5a) is affected.
- Version 4.3(4e) is affected.
- Version 4.1(3n) is affected.
- Version 4.3(4f) is affected.
- Version 4.2(3n) is affected.
- Version 4.3(5c) is affected.
- Version 4.2(3o) is affected.
- Version 4.3(5d) is affected.
- Version 4.3(6a) is affected.
- Version 4.3(6b) is affected.
- Version 4.3(5e) is affected.
- Version 4.3(6c) is affected.
- Version 4.2(3p) is affected.
- Version 6.0(1b) is affected.
- Version 6.0(1c) is affected.
- Version 4.3(6d) is affected.
- Version 6.0(1d) is affected.
- Version 6.0(1e) is affected.
- Version 4.3(6e) is affected.
- Version 6.0(1f) is affected.
- Version 4.3(6f) is affected.
- Version 6.0(2b) is affected.
- Version 6.0(1h) is affected.
- Version 4.2(3r) is affected.
- Version 6.0(2c) is affected.
- Version 4.3(6g) is affected.
- Version 6.0(2d) is affected.
- Version 4.3(6h) is affected.
- Version 4.2(3s) is affected.
- Version 4.3(6i) is affected.