CVE-2026-76504

CVE-2026-76504 is a critical-severity vulnerability in Cisco Catalyst Sd-wan Manager with a CVSS 3.x base score of 9.8. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2026-09-30). The underlying weakness is classified as CWE-177.

Key facts

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.

Frequently asked questions

What is CVE-2026-76504?
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.
How severe is CVE-2026-76504?
CVE-2026-76504 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-76504 being actively exploited?
Yes. CVE-2026-76504 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2026-09-30, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2026-76504?
CVE-2026-76504 primarily affects Cisco Catalyst Sd-wan Manager. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-76504?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
When was CVE-2026-76504 published?
CVE-2026-76504 was published on 2026-09-30 and last updated on 2026-10-03.

References

Affected products (2)

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