Answer in brief
CVE-2026-76456 records a High severity (CVSS 8.6) vulnerability in Cisco NX-OS Software Security Hardening Release: October 2026 - Improper Input Validation Vulnerabilities. The current sources do not mark it as known exploited. The current feed maps Cisco/Cisco NX-OS Software (generic), Cisco/Cisco NX-OS System Software in ACI Mode (generic), Cisco/Cisco Unified Computing System (Managed) (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.6. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Cisco/Cisco NX-OS Software (generic), Cisco/Cisco NX-OS System Software in ACI Mode (generic), Cisco/Cisco Unified Computing System (Managed) (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Cisco/Cisco NX-OS Softwaregeneric | 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) || 7.3(0)D1(1) || 7.3(4)D1(1) || 9.2(1) || 9.2(2t) || 9.2(3y) || 9.3(2) || 7.3(1)DY(1) || 8.1(1) || 8.2(2) || 8.3(2) || 7.3(2)D1(3a) || 9.2(4) || 8.1(2) || 7.3(3)D1(1) || 8.2(3) || 8.3(1) || 8.4(1) || 8.1(1b) || 7.3(0)DX(1) || 7.3(2)D1(1) || 9.3(1) || 7.3(2)D1(2) || 8.2(4) || 7.3(0)DY(1) || 9.3(1z) || 9.2(2) || 8.1(2a) || 7.3(2)D1(3) || 8.1(1a) || 8.4(1a) || 9.3(3) || 7.3(2)D1(1d) || 9.3(4) || 7.3(6)D1(1) || 8.2(6) || 9.3(5) || 8.4(2a) || 8.4(2b) || 8.5(1) || 9.3(6) || 8.4(4) || 7.3(7)D1(1) || 8.4(2c) || 9.3(5w) || 8.2(7) || 9.3(7) || 9.3(7k) || 7.3(8)D1(1) || 9.3(7a) || 8.2(7a) || 9.3(8) || 8.4(4a) || 8.4(2d) || 8.4(5) || 8.2(8) || 9.3(9) || 7.3(9)D1(1) || 8.4(6) || 8.4(2e) || 9.3(10) || 9.2(1a) || 8.2(9) || 10.3(1) || 8.4(7) || 10.3(2) || 8.4(6a) || 9.3(11) || 10.3(3) || 9.4(1) || 9.3(2a) || 8.4(2f) || 8.2(10) || 9.3(12) || 10.4(1) || 8.4(8) || 10.3(99w) || 10.3(3w) || 10.3(99x) || 10.3(3o) || 8.4(9) || 10.3(4) || 10.3(3p) || 10.3(4a) || 9.4(1a) || 10.4(2) || 10.3(3q) || 9.3(13) || 8.2(11) || 9.4(2) || 10.3(5) || 10.4(3) || 10.3(3x) || 10.3(4g) || 10.5(1) || 8.4(10) || 9.4(2a) || 10.3(3r) || 10.3(6) || 9.3(14) || 10.4(4) || 10.3(4h) || 10.5(2) || 10.5(1j) || 8.4(11) || 9.4(3) || 10.3(7) || 10.4(5) || 10.5(3) || 9.3(15) || 9.4(3a) || 10.4(4g) || 10.5(4) || 9.4(3b) || 8.4(12) || 10.6(1) || 10.5(3t) || 10.3(8) || 10.4(6) || 10.5(3s) || 10.5(3e) || 9.4(4) || 10.5(3o) || 9.3(16) || 10.6(1s) || 10.6(2) || 10.5(3p) || 9.4(5) || 10.3(9) || 10.6(2s) || 8.4(13) || 10.6(3) || 10.4(7) || 10.5(5) || 9.3(17) || 10.6(2n) || 10.6(3q) || 10.6(3o) || 10.6(3s) || 7.3(18)N1(1) | Not reported |
| Cisco/Cisco NX-OS System Software in ACI Modegeneric | 15.2(1g) || 15.2(2e) || 15.2(2f) || 15.2(2g) || 15.2(2h) || 15.2(3f) || 15.2(3e) || 15.2(3g) || 15.2(4d) || 15.2(4e) || 15.2(5c) || 15.2(5d) || 16.0(1g) || 15.2(5e) || 15.2(4f) || 15.2(6e) || 15.2(6h) || 16.0(1j) || 15.2(6g) || 15.2(7f) || 15.2(7g) || 16.0(2h) || 15.2(8d) || 16.0(2j) || 15.2(8e) || 16.0(3d) || 16.0(3e) || 15.2(8f) || 15.2(8g) || 15.3(1d) || 15.2(8h) || 16.0(4c) || 15.3(2a) || 15.2(8i) || 16.0(5h) || 15.3(2b) || 16.0(3g) || 16.0(5j) || 15.3(2c) || 16.0(6c) || 15.3(2d) || 16.1(1f) || 16.0(7e) || 16.0(8e) || 15.3(2e) || 16.0(8f) || 16.1(2f) || 16.1(2g) || 15.3(2f) || 16.0(9c) || 16.1(3f) || 16.0(9d) || 16.0(6h) || 16.0(8h) || 16.1(3g) || 16.0(9e) || 16.1(4h) || 16.1(5e) || 16.2(1g) || 16.0(9f) || 16.2(2e) | Not reported |
| Cisco/Cisco Unified Computing System (Managed)generic | 4.0(1a) || 4.1(1a) || 4.1(1b) || 4.0(4h) || 4.1(1c) || 4.0(4e) || 4.0(4g) || 4.0(2e) || 4.0(4a) || 4.0(2d) || 4.0(1b) || 4.0(4f) || 4.0(4c) || 4.0(1c) || 4.0(4b) || 4.0(2b) || 4.0(4d) || 4.0(2a) || 4.0(1d) || 4.0(4i) || 4.1(1d) || 4.1(2a) || 4.1(1e) || 4.1(2b) || 4.0(4k) || 4.1(3a) || 4.1(3b) || 4.1(2c) || 4.0(4l) || 4.1(4a) || 4.1(3c) || 4.1(3d) || 4.2(1c) || 4.2(1d) || 4.0(4m) || 4.1(3e) || 4.2(1f) || 4.1(3f) || 4.2(1i) || 4.1(3h) || 4.2(1k) || 4.2(1l) || 4.0(4n) || 4.2(1m) || 4.1(3i) || 4.2(2a) || 4.2(1n) || 4.1(3j) || 4.2(2c) || 4.2(2d) || 4.2(3b) || 4.1(3k) || 4.0(4o) || 4.2(2e) || 4.2(3d) || 4.2(3e) || 4.2(3g) || 4.1(3l) || 4.3(2b) || 4.2(3h) || 4.2(3i) || 4.3(2c) || 4.1(3m) || 4.3(2e) || 4.3(3a) || 4.2(3j) || 4.3(3c) || 4.3(4a) || 4.2(3k) || 4.3(4b) || 4.3(4c) || 4.2(3l) || 4.3(4d) || 4.3(2f) || 4.2(3m) || 4.3(5a) || 4.3(4e) || 4.1(3n) || 4.3(4f) || 4.2(3n) || 4.3(5c) || 4.2(3o) || 4.3(5d) || 4.3(6a) || 4.3(6b) || 4.3(5e) || 4.3(6c) || 6.0(1b) || 4.2(3p) || 6.0(1c) || 4.3(6d) || 6.0(1d) || 6.0(1e) || 4.3(6e) || 6.0(1f) || 4.3(6f) || 6.0(2b) || 6.0(1h) || 4.2(3r) || 6.0(2c) || 4.3(6g) || 6.0(2d) || 4.3(6h) || 4.2(3s) || 4.3(6i) | Not reported |
Published upstream
Oct 7, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 7, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 7, 2026
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-2026-76456 are related to improper input validation of special elements used in a command issue that are grouped under the Common Weakness Enumeration (CWE) CWE-20.
Quoted source text, attributed separately from HOL analysis.