Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability
This vulnerability is in the CISA Known Exploited Vulnerabilities catalog: attackers are using it. If you run Catalyst SD-WAN Manager, fix it now.
CISA required action: 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.
US federal civilian agencies must remediate by Oct 3, 2026.
No official fix confirmed yet
Until a fix ships, follow the vendor's mitigations and CISA's required action, limit exposure of affected systems, and watch this record for a patch.
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.
Source: NIST National Vulnerability Database. Official vulnerability data, reproduced as published.
| Product | Vendor | Source |
|---|---|---|
| Catalyst SD-WAN Manager | Cisco | KEV |
Sources: KEV = CISA Known Exploited Vulnerabilities catalog. Version details have not been published yet.
Developments from the last 30 days, newest first.
CVE-2026-76504 scored CVSS 9.8
Basis: NIST National Vulnerability Database
Cisco warns of new SD-WAN zero-day exploited in attacks
Source reporting says attackers are already exploiting this, so exposed Cisco networking & security systems are at immediate risk.
Basis: Reporting by BleepingComputer
CVE-2026-76504 added to CISA KEV: Cisco Catalyst SD-WAN Manager, Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability
CISA lists this as exploited in the wild. Unpatched Catalyst SD-WAN Manager systems are exposed to active attacks now.
Basis: CISA Known Exploited Vulnerabilities catalog
CISA lists this as exploited in the wild. Unpatched Cisco networking & security and Catalyst SD-WAN Manager systems are exposed to active attacks now.
Treat this as an emergency.
