Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability (CVE-2026-76504)
Severity: critical · Patch status: unknown · Since 2026-09-30 · CVE-2026-76504
Cisco Catalyst SD-WAN Manager contains a hex encoding vulnerability that could allow an unauthenticated, remote attacker to access an affected system with privileges of the admin user due to improper handling of URI encoding in an HTTP request. CISA added CVE-2026-76504 to its Known Exploited Vulnerabilities catalog on Sep 30, 2026, which means attackers are exploiting it in the wild.
What to do
- 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 agencies must remediate by Oct 3, 2026 (BOD 22-01); treat that as the outer limit.
Sources
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