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Vulnerability Intelligence

CVE-2026-76504

CriticalExploitedPublic exploit

Cisco Catalyst SD-WAN Manager System Account Authorization Bypass Vulnerability

Published Sep 30, 2026 · Updated Oct 3, 2026 · Also known as EUVD-2026-89950, GHSA-xqjc-v467-8fvf

Key Facts

Patch immediately
  • CVE-2026-76504 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Catalyst SD-WAN Manager (Cisco).
  • It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Sep 30, 2026. Public exploit code is available.
  • EPSS estimates a 1.8% probability of exploitation in the next 30 days.
  • Fixed versions are available, including Catalyst SD-WAN Manager 20.12.8.2, Catalyst SD-WAN Manager 20.15.6.1, Catalyst SD-WAN Manager 20.18.4.1.
  • Brandefense priority: patch immediately, because it is listed as exploited in the wild.

CVSS v3.1

9.8

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS (30-day exploit likelihood)

1.8%

Higher than 78.3% of all scored CVEs

Exploited in the wild

Yes

4 catalog listings

Public exploit code

Available

Proof-of-concept or weaponized module

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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.

Known-Exploited Catalog Listings

CatalogAddedRemediation dueRansomware use
CISA KEVSep 30, 2026Oct 3, 2026Not reported
Industry KEV feedSep 30, 2026Oct 3, 2026Not reported
CIRCL KEVSep 30, 2026Oct 3, 2026Not reported
ENISA EUVDSep 30, 2026n/aNot reported

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.

Affected Products

4 affected entries in total
ProductAffected versionsFixed in
Catalyst SD-WAN ManagerCisco26.2, >= 18.3.620.9.10.1

Patched Releases

Catalyst SD-WAN Manager

20.12.8.2, 20.15.6.1, 20.18.4.1, 20.9.10.1, 26.1.2.1

Timeline

  1. Publicly disclosed

    Sep 30, 2026

  2. Added to CISA KEV

    Sep 30, 2026

  3. Added to Industry KEV feed

    Sep 30, 2026

  4. Added to CIRCL KEV

    Sep 30, 2026

  5. Added to ENISA EUVD

    Sep 30, 2026

  6. Last updated

    Oct 3, 2026

Weakness Type

  • CWE-177 Improper Handling of URL Encoding (Hex Encoding)

References

FAQ

Common Questions.

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