Skip to content
Patcharo
Back to the results

Vulnerabilities

CriticalKEV

CVE-2026-76504 — Cisco Catalyst SD-WAN Manager System Account Authorization Bypass Vulnerability

CVE-2026-76504 · Cisco Catalyst SD-WAN Manager · CVSS 9.8 · KEV

In brief

Severity · CVSS
Critical9.8CVSS 3.1, Critical
EPSS
No score
CISA KEV
Known exploited, listed since 30 Sept 2026
Vendor
Cisco
Published · Modified
·
Last verified

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.

Weakness: CWE-177

Title, description and the vendor's statements are quoted from the CVE record; a vendor's advisory is summarised in Patcharo's words, with a link.

Affected and fixed versions

Per product and release branch, as the vendor's CVE record and official advisory state them. A fixed release is shown only when a document names it: the vendor's, or CERT-FR's for Check Point, with its source.

6 branches with a published fixed release · 4 branches to migrate

Cisco Catalyst SD-WAN Manager

Source: cisco-sa-sdwan-webauth-xr8beuuUCVE-2026-76504

  1. 26.2
    Affected versions< 26.2.1
    First fixed release26.2.1
  2. 26.1
    Affected versions< 26.1.2.1
    First fixed release26.1.2.1
  3. 20.18
    Affected versions< 20.18.4.1
    First fixed release20.18.4.1
  4. 20.15
    Affected versions< 20.15.6.1
    First fixed release20.15.6.1
  5. 20.12
    Affected versions< 20.12.8.2
    First fixed release20.12.8.2
  6. 20.9
    Affected versions< 20.9.10.1
    First fixed release20.9.10.1
  7. 18.4
    Affected versions18.4, 18.4.0.1, 18.4.1, 18.4.3
    First fixed releaseMigration to a fixed release required
  8. 18.3
    Affected versions18.3, 18.3.1, 18.3.1.1, 18.3.3
    11 releases listed18.3, 18.3.1, 18.3.1.1, 18.3.3, 18.3.3.1, 18.3.4, 18.3.5, 18.3.6, 18.3.6.1, 18.3.7, 18.3.8
    First fixed releaseMigration to a fixed release required
  9. 18.2
    Affected versions18.2
    First fixed releaseMigration to a fixed release required
  10. 17.2
    Affected versions17.2.4, 17.2.5, 17.2.6, 17.2.7
    7 releases listed17.2.4, 17.2.5, 17.2.6, 17.2.7, 17.2.8, 17.2.9, 17.2.10
    First fixed releaseMigration to a fixed release required

Remediation

Fix available

Vendor fix

  • Catalyst SD-WAN Manager 26.226.2.1
  • Catalyst SD-WAN Manager 26.126.1.2.1
  • Catalyst SD-WAN Manager 20.1820.18.4.1
  • Catalyst SD-WAN Manager 20.1520.15.6.1
  • Catalyst SD-WAN Manager 20.1220.12.8.2
  • Catalyst SD-WAN Manager 20.920.9.10.1

Upgrade to a fixed release listed above for your branch, or to a later fixed release the vendor explicitly supports.

Branches without a fix of their own: migrate to a fixed release

  • Catalyst SD-WAN Manager 18.4
  • Catalyst SD-WAN Manager 18.3
  • Catalyst SD-WAN Manager 18.2
  • Catalyst SD-WAN Manager 17.2

Cisco has released updates that fix this vulnerability; its advisory lists them.

SourceCisco Security Advisory cisco-sa-sdwan-webauth-xr8beuuU

Mitigation (vendor)

Cisco describes a workaround or a mitigation in its advisory.

SourceCisco Security Advisory cisco-sa-sdwan-webauth-xr8beuuU

CISA KEV 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).

Full CISA action

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.

CISA due date:

SourceCISA KEV

CERT-FR recommendation

Refer to the vendor's security bulletin to obtain patches (see Documentation section).

SourceCERTFR-2026-AVI-1246

Last verified 1 Oct 2026 at 09:29 UTC

Known exploitation

Added to CISA KEV on 30 Sept 2026

Federal remediation due date: 3 Oct 2026

The CISA required action is shown under Remediation.

No EPSS score available.

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

CERT-FR

1 document of the French national CERT (ANSSI) references this CVE.

Advisory (AVI)CERTFR-2026-AVI-1246Published 1 Oct 2026

Vulnerability in Cisco Catalyst SD-WAN

Security policy bypass

Summary

Une vulnérabilité a été découverte dans Cisco Catalyst SD-WAN. Elle permet à un attaquant de provoquer un contournement de la politique de sécurité. Cisco indique que la vulnérabilité CVE-2026-76504 est activement exploitée.

Recommendation

Refer to the vendor's security bulletin to obtain patches (see Documentation section).

Official document on cert.ssi.gouv.frread by Patcharo 1 Oct 2026 at 13:38 UTCMachine translation of the French text published by CERT-FR; a text whose translation did not pass Patcharo's checks stays in French. Identifiers, versions and links are copied unchanged.

Timeline

  1. Added to CISA KEV
  2. Published by the source
  3. Source record last modified
  4. Last verified by Patcharo
  5. CISA remediation due date

Official sources

References

Cisco · CISA Known Exploited Vulnerabilities · NVD · Cisco Security Advisory cisco-sa-sdwan-webauth-xr8beuuU

How Patcharo reads this

Affected and fixed releases come from the vendor's structured statements and are matched against exact versions; CVSS from NVD, exploitation from CISA KEV and the vendor's own advisory, probability from FIRST EPSS. Missing data stays Unknown and never becomes Not affected.

Read the methodologyRead the guide: Cisco Secure Firewall release trains: Threat Defense, Management Center and ASA versions explained