TI-2026-69220 Aliases CVE-2026-76456 GHSA-w55m-537w-hc8q

Cisco NX-OS input validation flaw allows remote service disruption

MEDIUM 43CWE-20Published 2026-10-07 · Updated 2026-11-07

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: None · None · High
Fix status: No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

Cisco NX-OS Software, Cisco NX-OS System Software in ACI Mode and Cisco Unified Computing System (Managed) are affected. Improper input validation (CWE-20) of special elements used in a command lets the software mishandle crafted input. An unauthenticated remote attacker can disrupt the availability of an affected device without any user interaction.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00278 20th percentileScored 2026-11-07

Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
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); 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)	—	No fix listed	CNA
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); 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)	—	No fix listed	CNA
Cisco	Cisco Unified Computing System (Managed)	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)	—	No fix listed	CNA

Cisco NX-OS Software VendorCisco Affected 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) Fixed in — No fix listed CNA
Cisco NX-OS System Software in ACI Mode VendorCisco Affected 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) Fixed in — No fix listed CNA
Cisco Unified Computing System (Managed) VendorCisco Affected 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) Fixed in — No fix listed CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:o:cisco:nx-os::::::::	—	—	Cisco

cpe:2.3:o:cisco:nx-os:*:*:*:*:*:*:*:* Versions — — ·Cisco

Remediation

The sources list no fixed version for Cisco NX-OS Software, Cisco NX-OS System Software in ACI Mode or Cisco Unified Computing System (Managed).

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Timeline

2026-10-07 Threatist record created from CVE-2026-76456
2026-10-07 CISA SSVC decision points changed
2026-10-07 Alias added: GHSA-w55m-537w-hc8q

References

Other 1

cisco-sa-hardening-nxosw1-cWzSbtR

TI-2026-74174 Arbitrary file write in Cisco Secure Email Gateway via AMP feature KEVCVSS 3.1CRITICAL 9.8
TI-2026-53490 Cisco Catalyst SD-WAN Manager System Account Authorization Bypass Vulnerability KEVCVSS 3.1CRITICAL 9.8
TI-2026-53489 Cisco Secure Email Gateway SQL Injection Vulnerability KEVCVSS 3.1CRITICAL 9.8
TI-2026-53488 Cisco Identity Services Engine Authentication Bypass Vulnerability KEVCVSS 3.1CRITICAL 10.0
TI-2026-16388 Cisco Catalyst SD-WAN Controller Authentication Bypass Vulnerability KEVCVSS 3.1CRITICAL 10.0
TI-2026-16344 Cisco Secure Firewall Management Center Software Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 10.0

See all 7059 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences