# CVE-2026-20010: Cisco Nexus 3000 and 9000 Series Switches Link Layer Discovery Protocol Denial of Service Vulnerability

> An adjacent attacker can cause a Cisco Nexus switch to reload by sending a crafted LLDP packet, resulting in a denial of service.

- **Severity:** High 7.4 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 Feb 2026
- **Updated:** 25 Feb 2026
- **Also known as:** GHSA-8f59-hcpc-g3hp

## What is CVE-2026-20010?

CVE-2026-20010 is a high-severity denial of service vulnerability in Cisco NX-OS Software, published on 25 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability in the Link Layer Discovery Protocol (LLDP) feature of Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause the LLDP process to restart, which could cause an affected device to reload unexpectedly.

This vulnerability is due to improper handling of specific fields in an LLDP frame. An attacker could exploit this vulnerability by sending a crafted LLDP packet to an interface of an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a denial of service (DoS) condition.
Note: LLDP is a Layer 2 link protocol. To exploit this vulnerability, an attacker would need to be directly connected to an interface of an affected device, either physically or logically (for example, through a Layer 2 Tunnel configured to transport the LLDP protocol).

Weakness: CWE-805 (Buffer Access with Incorrect Length Value)

## Which versions are affected by CVE-2026-20010?


## How do I fix CVE-2026-20010?

No fix has been published for CVE-2026-20010 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-20010 being exploited?

There is no known exploitation of CVE-2026-20010 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-20010 and fix it if it is affected.

What it is: CVE-2026-20010 is a high-severity denial of service vulnerability in Cisco NX-OS Software, published on 25 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-20010 in the wild and no public exploit code.

Affected product: Cisco NX-OS Software. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-20010/ (Markdown: https://insights.sbomify.com/CVE-2026-20010/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-20010
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-20010
- OSV: https://osv.dev/vulnerability/CVE-2026-20010

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-20010/
Summaries are generated and may contain mistakes; the official description above is the record.