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Fencer Intel
critical 9.8

CVE-2026-76504 kev in the critical feed json

Cisco Catalyst SD-WAN Manager System Account Authorization Bypass Vulnerability

published last mo. modified last mo. also EUVD-2026-89950

cvss
9.8
version 3.1, CNA
cisa kev
Exploited
added 2026-09-30
epss
38.9%
EPSS 38.9% chance of exploitation in 30 days, percentile 98%
public exploits
0
none known

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.

Patch / fix

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.

  • cisco catalyst_sd-wan_manager 20.9.10.1, 20.12.8.2, 20.15.6.1, 20.18.4.1, 26.1.2.1

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Timeline

  1. CISA SSVC: exploitation active
  2. Added to CISA KEV
  3. Published
  4. CISA patch deadline

Known exploited

Added
last mo.
Patch by
2026-10-03 (last mo.)
Ransomware
Not known
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.
Vendor, product
Cisco, Catalyst SD-WAN Manager
CISA name
Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability

CISA SSVC

Exploitation
Active, exploited in the wild
Automatable
yes
Technical impact
total
Assessed
last mo.

Exploit prediction

38.93% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Cisco Cisco Catalyst SD-WAN Manager

Classification

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

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.