CVE-2026-76504: Cisco Catalyst SD-WAN Manager System Account Authorization Bypass Vulnerability
An authority record changed. This is a change in what is asserted about exploitation, not in how the vulnerability is described.
CVE record, CISA KEV and EPSS as of 2026-10-25.
CVEs like this one computed, by meaning
What to do now held facts and links
- CISA requires: 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. The federal deadline has passed: overdue since 2026-10-03. CISA KEVCISA's notes for this entry: sec.cloudapps.cisco.com cisa.gov cisa.gov
- Upgrade to the fixed version for your release line, or later: catalyst sd-wan manager 20.12.8.2; catalyst sd-wan manager 20.15.6.1; catalyst sd-wan manager 20.18.4.1; catalyst sd-wan manager 20.9.10.1; catalyst sd-wan manager 26.1.2.1 upper bounds of the CVE record's affected ranges
- Record your decision, dated and frozen with today's evidence: patch by a date · mitigated by a compensating control · deferred · accepted the risk · not affected
- Check your version against the ranges this record publishes.
What it is stated by the CNA
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 Improper Handling of URL Encoding (Hex Encoding)
- affected
- Cisco Catalyst SD-WAN Manager
- published ranges
- cisco catalyst sd-wan manager < 20.9.10.1; cisco catalyst sd-wan manager >= 20.12 < 20.12.8.2; cisco catalyst sd-wan manager >= 20.15 < 20.15.6.1; cisco catalyst sd-wan manager >= 20.18 < 20.18.4.1; and 2 more on the CVE page
- first unaffected version, by branch
- catalyst sd-wan manager 20.12.8.2; catalyst sd-wan manager 20.15.6.1; catalyst sd-wan manager 20.18.4.1; catalyst sd-wan manager 20.9.10.1; catalyst sd-wan manager 26.1.2.1
- severity
- 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- assigned by
- cisco
- published
- 2026-09-30
check us sec.cloudapps.cisco.com
Authority held, dated
- CISA KEV
- listed
- added
- 2026-09-30
- remediation due
- 2026-10-03
- ransomware use
- unknown
- remediation status
- overdue since 2026-10-03
- exploit code
- 1 public proof-of-concept repository, first seen 2026-09-30 (PoC-in-GitHub).
A KEV listing is an assertion of observed exploitation. It is the only element on this page that makes that claim.
What moved held, dated
| date | EPSS | event |
|---|---|---|
| 1 Oct 2026 | 0.01096 | |
| 2 Oct 2026 | 0.01575 | |
| 6 Oct 2026 | 0.01819 | |
| 25 Oct 2026 | 0.38928 | crossed 0.10 |
4 observations held. A step marked with a scoring model moved because the measurement was replaced, not because the vulnerability changed.
Outside the record researched, cited
This section reads the record's references and adds cited findings from outside it. It needs an account. Everything above is held facts and is complete without it.
What would change this brief held, dated
- CISA KEV
- Listed, added 2026-09-30. Due 2026-10-03. A changed deadline or a change in ransomware use changes this brief.
- exploit probability
- 0.39 on 2026-10-25 (FIRST's EPSS, a probability and not evidence of exploitation). Next band line: 50% (0.50). Crossing a line changes this brief.
- fix
- Held: catalyst sd-wan manager 20.12.8.2; catalyst sd-wan manager 20.15.6.1; catalyst sd-wan manager 20.18.4.1; catalyst sd-wan manager 20.9.10.1; catalyst sd-wan manager 26.1.2.1. A newer fix from the CNA or OSV changes this brief.
How to check this
Every value above is held with two dates: when it was true upstream (as_of) and when we recorded it (tx_from). Re-derive the exploit probability as it stood on any date:
SELECT value, source, source_version, as_of, tx_from
FROM volatile_valid_as_of('CVE-2026-76504', '2026-10-30T23:59:59.999999Z', now());