Cisco NX-OS October 2026 hardening: six CVEs and fixes
Check affected Cisco MDS, Nexus, and UCS branches, understand grouped CVSS scores, and choose the first fixed release.
Think of the advisory as one inspection report grouping faults by type, while each equipment family gets its own repair chart. The CWE category describes a weakness class; it does not mean all six CVEs share one code path.
CVE and weakness categories
| CVE | CWE | Maximum CVSS in category |
|---|---|---|
| CVE-2026-76453 | CWE-707 | 8.8 |
| CVE-2026-76455 | CWE-284 | 9.8 |
| CVE-2026-76456 | CWE-20 | 8.6 |
| CVE-2026-76457 | CWE-125 | 8.6 |
| CVE-2026-76458 | CWE-703 | 8.6 |
| CVE-2026-76459 | CWE-787 | 9.8 |
First fixed release by product family
The advisory covers the listed affected hardware families. Use the precise product mode and release branch; the fixed release in one row does not apply to another family.
| Product family and mode | Affected branch | First fixed release / required action |
|---|---|---|
| MDS 9000 | 9.3 and earlier | Migrate to a fixed release; confirm a compatible target with Cisco. |
| MDS 9000 | 9.4 | 9.4(5a) |
| Nexus 3000 + Nexus 9000 standalone NX-OS | 10.3 and earlier | 10.3(10) |
| Nexus 3000 + Nexus 9000 standalone NX-OS | 10.4 | 10.4(8) |
| Nexus 3000 + Nexus 9000 standalone NX-OS | 10.5 | 10.5(6) |
| Nexus 3000 + Nexus 9000 standalone NX-OS | 10.6 | 10.6(4) |
| Nexus 7000 | 8.3 and earlier | Migrate to a fixed release; confirm a compatible target with Cisco. |
| Nexus 7000 | 8.4 | 8.4(14) |
| Nexus 9000 ACI | 16.0 and earlier | 16.0(9h) |
| Nexus 9000 ACI | 16.1 | 16.1(6g) |
| Nexus 9000 ACI | 16.2 | 16.2(3g) |
| UCS 6300/6400/6500/6600 and UCS X-Series 9108 | 4.2 and earlier | Migrate to a fixed release; confirm a compatible target with Cisco. |
| UCS 6300/6400/6500/6600 and UCS X-Series 9108 | 4.3 | UCS Manager 4.3(6j); Intersight 4.3(6.260049); 9108 also 4.3(6.260059) |
| UCS 6300/6400/6500/6600 and UCS X-Series 9108 | 6.0 | UCS Manager 6.0(2e); Intersight 6.0(2.260080) |
Choose and verify the correct Cisco NX-OS fix
Identify the platform
Record the exact product family and mode: Nexus standalone NX-OS and Nexus 9000 in ACI use different rows.
Record the release branch
Capture the installed software release and, for UCS, whether UCS Manager or Intersight manages the fabric.
Match the advisory table
Use only the row for that product family and branch. Where Cisco says to migrate to a fixed release, confirm a compatible target with Cisco instead of assuming a train.
Verify before change
Recheck Cisco’s advisory for current affected/fixed release data and follow the platform’s upgrade procedure.
- Inventory MDS, Nexus, and UCS devices, including standby and high-availability peers.
- For each Nexus 9000, record standalone NX-OS versus ACI mode before selecting a target.
- For UCS, record UCS Manager versus Intersight and apply the corresponding fixed release.
- Upgrade to the listed first fixed release or a later supported release in that branch; migrate where instructed.
- Do not treat a CVSS maximum as the score of every underlying issue or infer that the AI models found a particular CVE.