CVE-2026-20127

CRITICAL10.0

CISA KEV

Published 2026-02-25 · Updated 2026-06-17 · Source psirt@cisco.com

Summary

CVE-2026-20127 is a critical-severity (CVSS 10.0) vulnerability in Cisco Catalyst SD-WAN Controller and Manager. CISA added it to the Known Exploited Vulnerabilities catalog on February 25, 2026, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by February 27, 2026. CISA does not currently list it as used in ransomware campaigns. Cisco has 102 vulnerabilities in the KEV catalog, 7 of them linked to ransomware.

All 102 known-exploited Cisco vulnerabilities →

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. 

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

CWE-287CWE-287

CISA Known-Exploited Vulnerability

Product: Cisco — Catalyst SD-WAN Controller and Manager

Name: Cisco Catalyst SD-WAN Controller and Manager Authentication Bypass Vulnerability

Date added: 2026-02-25 · Due: 2026-02-27

Required action: Please adhere to CISA’s guidelines to assess exposure and mitigate risks associated with Cisco SD-WAN devices as outlines in CISA’s Emergency Directive 26-03 (URL listed below in Notes) and CISA’s “Hunt & Hardening Guidance for Cisco SD-WAN Devices (URL listed below in Notes). Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available.

References

View on NVD

More exploited Cisco vulnerabilities

Most recently added to CISA KEV

CVE-2026-76418
Secure Firewall ASA Software and Cisco Secure FTD Software — Cisco Secure Firewall ASA Software and Cisco Secure FTD Software Unchecked Return Value to NULL Pointer Dereference Vulnerability
added 2026-10-29
CVE-2026-76519
Secure Email Gateway — Cisco Secure Email Gateway Relative Path Traversal Vulnerability
added 2026-10-14
CVE-2026-76504
Catalyst SD-WAN Manager — Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability
added 2026-09-30
CVE-2026-76460
Identity Services Engine — Cisco Identity Services Engine Incorrect Use of Privileged APIs Vulnerability
added 2026-09-16
CVE-2026-76461
Secure Email Gateway — Cisco Secure Email Gateway SQL Injection Vulnerability
added 2026-09-14
CVE-2026-20079
Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management — Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability
added 2026-09-09

View all →

Related CVEs

Same severity, most recent

CVE-2026-109469
Authorization bypass through user-controlled key in Entra Device Registration allows an unauthorized attacker to elevate privileges over a network.
2026-11-06 · score 10.0
CVE-2026-68935
Chartbrew is an open-source web application for creating charts from databases and APIs. In versions 4.8.5 through 5.2.2, API connection creation and update operations accept the internal allowPrivateHost field from user input. An authenticated user with permission to manage API connections can enable this field to bypass private and reserved-network destination restrictions. An upgrade migration also enables the override on pre-existing API connections. The per-connection setting takes precedence over CB_ALLOW_PRIVATE_NETWORK_CALLS , so disabling that instance option does not protect connections with the override enabled. Successful exploitation allows requests to internal HTTP services reachable from the Chartbrew server, potentially disclosing information or triggering unauthorized actions depending on the target service. Recognized cloud metadata endpoints remain separately blocked. This issue is fixed in version 5.2.3.
2026-11-06 · score 9.1
CVE-2026-59104
UgCS server before 6.2 contains an authentication bypass in the HCI protocol login handler (LoginHandler) exposed on TCP port 3334. When the user database contains exactly one user (the default single-operator installation), a LoginRequest with empty userLogin and userPassword fields is interpreted as \"use the only user\" rather than as invalid credentials, and the server returns a fully authenticated session. Because the service listens on all interfaces (0.0.0.0) without TLS by default, an unauthenticated remote attacker with network access to port 3334 can obtain an authenticated session without knowing any credential and then issue privileged commands, including commanding connected drones and uploading flight routes.
2026-11-06 · score 9.8
CVE-2026-86044
JupyterLab Desktop is the cross-platform desktop application for JupyterLab. Prior to 4.6.2-1, JupyterLab Desktop exposed getServerInfo to the renderer without confirming that the current page still had the local Jupyter server origin. In a local managed session using JupyterLab before 4.4.8, an attacker can place a crafted MathJax link in an untrusted notebook. If a victim opens the notebook and clicks the link, the existing renderer navigates to an attacker-controlled site while retaining access to the preload bridge. The site can call getServerInfo to obtain the local server URL and authentication token, then use the Jupyter REST API to create and trust a notebook that executes arbitrary code as the victim. Users whose environment already uses JupyterLab 4.4.8 or later are unaffected because the corrected link handling breaks the first step of the chain. This vulnerability is fixed in 4.6.2-1.
2026-11-06 · score 9.6
CVE-2026-85295
Chartbrew is an open-source web application that can connect directly to databases and APIs and use the data to create charts. Prior to 5.2.3, four authentication helpers accepted session tokens signed with CB_SECRET, including known, weak, or shipped-default values. The vulnerable surface is session JWT fallback in server/modules/verifyToken.js, verifyUser.js, getUserFromToken.js, and socketManager.js across the API and socket layer. A stock source or repository Docker Compose deployment retains a known, weak, or default CB_SECRET and an attacker submits a forged HS256 token decoding to a target user id. Knowing the symmetric secret lets the attacker create a token that the legacy verification fallback accepts as the target user without that user's password or two-factor authentication. The condition includes stock source and repository Docker Compose installs and any otherwise known or weak CB_SECRET; a bare container where CB_SECRET is undefined is not affected by this fallback path. A forged session impersonates the chosen user across the entire API and socket layer and exercises that user's Chartbrew privileges. This issue is fixed in version 5.2.3.
2026-11-06 · score 9.8