CVE-2026-76504: Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on , the same day the CVE record was published.
- How likely is exploitation in the next 30 days?
- 38.9%
EPSS score, percentile 98.6 of all scored records
- How severe?
- 9.8 Critical
CVSS v3.1 base score, given by the CNA
- What should I do?
CISA deadline . Apply mitigations in accordance with vendor instructions … Full text
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected
- 20.1.12
- 19.2.1
- 18.4.4
- 18.4.5
- 20.1.1.1
- 20.1.1
and 6 more in the table below
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
What to do
Required action, set by CISA
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.
CISA due date for this action: .
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
Linked from CISA's catalog entry
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-webauth-xr8beuuU
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
- https://nvd.nist.gov/vuln/detail/CVE-2026-76504
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | 20.1.12 |
| Affected | 19.2.1 |
| Affected | 18.4.4 |
| Affected | 18.4.5 |
| Affected | 20.1.1.1 |
| Affected | 20.1.1 |
| Affected | 19.3.0 |
| Affected | 19.2.2 |
| Affected | 19.2.099 |
| Affected | 18.3.6 |
| Affected | 18.3.7 |
| Affected | 19.2.0 |
Versions not listed are: unknown.
And 403 more version entries in the CVE record.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
About this vulnerability
Cisco Catalyst SD-WAN Manager contains a hex encoding vulnerability that could allow an unauthenticated, remote attacker to access an affected system with privileges of the admin user due to improper handling of URI encoding in an HTTP request.
Summary: CISA's KEV catalog, as of .
- CISA added CVE-2026-76504 to its Known Exploited Vulnerabilities (KEV) catalog on 30 Sep 2026.
- CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
- The due date CISA sets for the required action is 3 Oct 2026.
- The CVE record was published on 30 Sep 2026, the same day it was added to KEV.
- The CVE record carries a CVSS v3.1 base score of 9.8 (Critical), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 38.9% (percentile 98.6), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable yes, technical impact total.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of . About the data.
Description
Cisco Catalyst SD-WAN Manager System Account Authorization Bypass Vulnerability
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.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
Weakness
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| Added to CISA KEV | |
| CVE record last updated | |
| CISA due date for the required action |
References
More exploited Cisco vulnerabilities
- CVE-2026-76519: Cisco Secure Email Gateway Relative Path Traversal Vulnerability
- CVE-2026-76460: Cisco Identity Services Engine Incorrect Use of Privileged APIs Vulnerability
- CVE-2026-76461: Cisco Secure Email Gateway SQL Injection Vulnerability
- CVE-2026-20079: Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability
- CVE-2026-20349: Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection Vulnerability
- CVE-2026-20316: Cisco Secure Firewall Management Center Use of Hard-coded Password Vulnerability