CVE-2026-76504
CriticalCisco Catalyst SD-WAN Manager Hex Encoding Vulnerability
- Published
- Sep 30, 2026
- Updated
- Oct 3, 2026
- Vendor
- Cisco
- Affected versions
- See affected products
- Weakness
- CWE-177
Summary
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.
Severity
Critical (9.8)CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products
- Cisco Catalyst Sd-wan Manager < 20.9.10.1
- Cisco Catalyst Sd-wan Manager >= 20.12, < 20.12.8.2
- Cisco Catalyst Sd-wan Manager >= 20.15, < 20.15.6.1
- Cisco Catalyst Sd-wan Manager >= 20.18, < 20.18.4.1
- Cisco Catalyst Sd-wan Manager >= 26.1, < 26.1.2.1
- Cisco Catalyst Sd-wan Manager 26.2
Exploitation status
Actively exploited
Listed in the CISA Known Exploited Vulnerabilities catalog on Sep 30, 2026. Federal remediation due: Oct 3, 2026.
Technical details
Technical analysis has not been written for this record yet.
Mitigation & remediation
- 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.