NVD / CVE Program· CNA cisco

CVE-2026-20212: Cisco Nexus 3000 and 9000 Series Switches Silicon One Hardware Abstraction Layer Remote Code Execution Vulnerability

Noroxi assessment

Priority: Monitor (action score 39/100)

Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
Probability of exploitation in the next 30 days: 0.83% (FIRST EPSS); higher than 57.7% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
According to the record, no fixed version is available yet.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A vulnerability in the Silicon One integration for Cisco Nexus 9000 Series Switches could allow an unauthenticated, remote attacker to execute code with root privileges. This vulnerability exists because TCP ports 43210 and 43211 are accessible in the default Layer 3 (L3) virtual routing and forwarding (VRF). A successful exploit could allow the attacker to connect to an affected device and send crafted input that could be executed as code with root privileges. The exploitation of this vulnerability could also cause the S1HAL process to crash, which could cause the device to reload.

CriticalCVSS 9.8 · v3.1—Proof of concept No fix recorded

pre-auth RCE

Published: Sep 2, 2026
Updated: Sep 3, 2026
EPSS: 0.8% · 57th percentile
CWE: CWE-1327

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 39 / 40 · 9.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.8%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · cisco: 9.8; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
Proof of concept exists, no weaponized module
No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

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Versions reported by the vendor

Affected version ranges reported by the assigning authority (cisco). Independent of NVD's CPE analysis and usually ahead of it.

Cisco Cisco NX-OS Software
- 10.3(1), 10.3(2), 10.3(3), 10.4(1), 10.3(99w), 10.3(3w), 10.3(99x), 10.3(3o), 10.3(4), 10.3(3p), 10.3(4a), 10.4(2) … (+28)affected

Same product

cisco: all records

Other highest-scoring records for the same primary product.

CVE-2026-76455Cisco NX-OS Software Security Hardening Release: October 2026 - Improper Access Control Vulnerabilities
40Plan
CVE-2026-76501Cisco Nexus 9000 Series Switches SRv6 OAM (NGOAM) Remote Code Execution Vulnerability
39Monitor
CVE-2026-76486Cisco Nexus 3000 and 9000 Series Switches VXLAN OAM (NGOAM) Remote Code Execution Vulnerability
39Monitor

Published before and after this one in the same product

← EarlierCVE-2026-20051Feb 25, 2026 · Cisco Nexus 3600-R and 9500-R Series Switching Platforms Layer 2 Loop Denial of Service Vulnerability
29Monitor
← EarlierCVE-2026-20171May 20, 2026 · Cisco Nexus 3000 and 9000 Series Border Gateway Protocol Denial of Service Vulnerability
27Monitor
Later →CVE-2026-20032Oct 7, 2026 · Cisco NX-OS Software Python Sandbox Escape Vulnerability
17Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
Source	Kind	Date
Proof-of-concept repository on GitHub	stars:1	2026-09-03

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

PublishedSep 2, 2026
First PoCSep 3, 2026same day
TodayNov 8, 2026+67 d

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

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Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).