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ExploitedIn CISA KEVFix available

CVE-2026-76504

Cisco Catalyst SD-WAN Manager System Account Authorization Bypass Vulnerability

Exploitation confirmed. First attested on 2026-09-30 by CISA-ADP, CISA KEV, GCVE · previdian, GCVE · shadowserver.

  • Published2026-09-30
  • Fixed in26.1.2.1 · 20.18.4.1 · 20.15.6.1 · 20.12.8.2 · 20.9.10.1
  • WeaknessCWE-177

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2026-09-30Added to the CISA KEV catalogCISA KEV
  2. 2026-09-30Listed as exploited by GCVEGCVE
  3. 2026-09-30Exploitation first reportedCISA KEV
  4. 2026-09-3013:17CVE publishedNVD
  5. 2026-09-3017:40SSVC exploitation set to activeCISA-ADP
  6. 2026-10-2523:12EPSS crossed 10 %FIRST EPSS

Versions per branch

NVD
Cisco catalyst sd-wan manager
BranchAffectedFixed in
26.1≥ 26.1, < 26.1.2.126.1.2.1
20.18≥ 20.18, < 20.18.4.120.18.4.1
20.15≥ 20.15, < 20.15.6.120.15.6.1
20.12≥ 20.12, < 20.12.8.220.12.8.2
20.9< 20.9.10.120.9.10.1
26.2= 26.2no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA1 product

As cisco, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • Cisco Catalyst SD-WAN Managerother versions: unknown
    Affected
    • = 20.1.12no fix stated
    • = 19.2.1no fix stated
    • = 18.4.4no fix stated
    • = 18.4.5no fix stated
    • = 20.1.1.1no fix stated
    • = 20.1.1no fix stated
    • = 19.3.0no fix stated
    • = 19.2.2no fix stated

    407 more version lines in the CVE record.

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-10-02

Fix

  1. Update Cisco catalyst sd-wan manager to 26.1.2.1 · 20.18.4.1 · 20.15.6.1 · 20.12.8.2 · 20.9.10.1
  2. CISA’s 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.due 2026-10-03

Advisories and patches

Detection

read 2026-11-06 06:14 UTC
Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

CISA Known Exploited Vulnerability

Date Added
2026-09-30
Patch Due Date
2026-10-03
Ransomware Use
Unknown
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.

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
2026-09-30
Last Modified
2026-10-03
NVD status
Analyzed
GitHub Advisory
GHSA-xqjc-v467-8fvf

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.

Is CVE-2026-76504 actively exploited?

Yes. CVE-2026-76504 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2026-10-03.

What is the CVSS score for CVE-2026-76504?

CVE-2026-76504 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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