CVE-2026-76504

Undergoing Analysis

Published: 30 Sept 2026, 13:04

Last modified:30 Sept 2026, 19:58

Vulnerability Summary

Overall Risk (default)

high

70/100

CVSS Score

9.8 CRITICAL

v3.1 (cve.org)

EPSS Score

No data

KEV

Listed

CISA

1 listing

Ransomware

No reports

Public exploits

None found

Dark Web

Not detected

Timeline

30 Sept 2026, 13:04

Published

Vulnerability first disclosed

30 Sept 2026, 00:00

Added to CISA KEV

Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability

30 Sept 2026, 19:58

Last Modified

Vulnerability information updated

03 Oct 2026, 00:00

CISA Remediation Due

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Description

A vulnerability in the API session-based authentication management of Cisco Catalyst SD-WAN Manager could allow an unauthenticated, remote attacker to access an affected system with privileges of the admin user. This vulnerability is due to improper handling of URI encoding in an HTTP request, which allows the request to bypass an authentication rule that is intended to restrict access to a specific API endpoint. An attacker could exploit this vulnerability by sending a crafted HTTP request to the API of the affected system. A successful exploit could allow the attacker to bypass authentication and gain access to the API as the admin user.

CVSS Metrics

v3.1•CRITICAL•Score: 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Techniques & Countermeasures

CWE-177•Improper Handling of URL Encoding (Hex Encoding)
The product does not properly handle when all or part of an input has been URL encoded.

Affected Systems

cisco•cisco catalyst sd-wan manager
18.3.6 | 18.3.7 | 18.3.8 | 17.2.10 | 18.3.6.1 | 18.2.0 | 18.4.3 | 18.4.1 | 17.2.8 | 18.3.3.1 | 18.4.0 | 18.3.1 | 17.2.6 | 17.2.9 | 18.3.4 | 17.2.5 | 18.3.1.1 | 18.3.5 | 18.4.0.1 | 18.3.3 | 17.2.7 | 17.2.4 | 18.3.0