# CVE-2026-20127: Cisco Catalyst SD-WAN Controller and Manager Authentication Bypass

> Unauthenticated remote attackers can bypass peering authentication to gain administrative privileges and manipulate SD-WAN network configurations.

- **Severity:** Critical 10.0 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Yes, since 25 Feb 2026 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 Feb 2026
- **Updated:** 16 Jun 2026
- **Also known as:** GHSA-p4cq-46q3-jr7w

## What is CVE-2026-20127?

CVE-2026-20127 is a critical authentication bypass vulnerability in Cisco Catalyst Sd-Wan Manager, published on 25 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the peering authentication in Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, and Cisco Catalyst SD-WAN Validator, formerly SD-WAN vBond, could allow an unauthenticated, remote attacker to bypass authentication and obtain administrative privileges on an affected system.

This vulnerability exists because the peering authentication mechanism in an affected system is not working properly. An attacker could exploit this vulnerability by sending crafted requests to an affected system. A successful exploit could allow the attacker to log in to an affected Cisco Catalyst SD-WAN Controller as an internal, high-privileged, non-root user account. Using this account, the attacker could access NETCONF, which would then allow the attacker to manipulate network configuration for the SD-WAN fabric. 

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-20127?

It affects 3 products.


Products: Cisco Catalyst Sd-Wan Manager, Cisco Sd-Wan Vbond Orchestrator, Cisco Sd-Wan Vsmart Controller.

## How do I fix CVE-2026-20127?

No fix has been published for CVE-2026-20127 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 27 Feb 2026.

## Is CVE-2026-20127 being exploited?

Yes. Attackers have exploited CVE-2026-20127 in the wild since at least 25 Feb 2026.

Public exploit code:

- https://github.com/zerozenxlabs/CVE-2026-20127---Cisco-SD-WAN-Preauth-RCE (github_poc): https://github.com/zerozenxlabs/CVE-2026-20127---Cisco-SD-WAN-Preauth-RCE
- An exploit for the Cisco Catalyst SD-WAN Controller authentication bypass vulnerability, CVE-2026-20127 (github_poc): https://github.com/sfewer-r7/CVE-2026-20127
- Cisco Catalyst SD-WAN 身份验证绕过漏洞(CVE-2026-20127)利用EXP (github_poc): https://github.com/BugFor-Pings/CVE-2026-20127_EXP
- https://github.com/yonathanpy/CVE-2026-20127-Cisco-SD-WAN-Preauth-RCE (github_poc): https://github.com/yonathanpy/CVE-2026-20127-Cisco-SD-WAN-Preauth-RCE
- https://github.com/gigachadusers/cve-2026-20127 (github_poc): https://github.com/gigachadusers/cve-2026-20127
- Cisco Catalyst SD-WAN Controller Authentication Bypass (metasploit)

## Other vulnerabilities in Cisco Catalyst Sd-Wan Manager

- [CVE-2026-20182](https://insights.sbomify.com/CVE-2026-20182/): Cisco Catalyst SD-WAN Controller Authentication Bypass (critical 10.0, exploited in the wild)
- [CVE-2026-76504](https://insights.sbomify.com/CVE-2026-76504/): Cisco Catalyst SD-WAN Manager Hex Encoding (critical 9.8, exploited in the wild)
- [CVE-2026-20245](https://insights.sbomify.com/CVE-2026-20245/): Cisco Catalyst SD-WAN Manager Improper Encoding or Escaping of Output (high 7.8, exploited in the wild)
- [CVE-2022-20775](https://insights.sbomify.com/CVE-2022-20775/): Cisco SD-WAN Path Traversal (high 7.8, exploited in the wild)
- [CVE-2026-20128](https://insights.sbomify.com/CVE-2026-20128/): Cisco Catalyst SD-WAN Manager Storing Passwords in a Recoverable Format (high 7.5, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-20127 and fix it if it is affected.

What it is: CVE-2026-20127 is a critical authentication bypass vulnerability in Cisco Catalyst Sd-Wan Manager, published on 25 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2026-20127 in the wild since at least 25 Feb 2026.

Affected product: Cisco Catalyst Sd-Wan Manager. 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-2026-20127/ (Markdown: https://insights.sbomify.com/CVE-2026-20127/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-20127
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-20127
- OSV: https://osv.dev/vulnerability/CVE-2026-20127

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-20127/
Summaries are generated and may contain mistakes; the official description above is the record.