CVE-2026-76504Cisco Catalyst SD-WAN Manager System Account Authorization Bypass Vulnerability
- 9.8CriticalCVSS base score
- 38.9%Exploitation in 30 daysEPSS · top 1.4% of all CVEs
- YesKnown exploitedin CISA's KEV since 30 Sept 2026
- YesPublic exploitsa reference or SSVC says so
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.
Exploited in the wild
CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability.
- Added
- 30 Sept 2026
- Fix due (US federal)
- 3 Oct 2026
- Used by ransomware
- Not known
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.
ENISA's EU Vulnerability Database lists it as exploited, from CISA's KEV, since 30 Sept 2026.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. CISA's SSVC rates its exploitation: it is being exploited.
Timeline
ID reserved
By cisco
- 42 days later
· 42 days later
Published
Added to CISA KEV
Known exploited in the wild
- 2 days later
· 2 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| ciscoCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Analyzed | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 38.9% · top 1.4% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: active · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
Cisco · Cisco Catalyst SD-WAN Manager
- 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
- affected 18.3.8
- affected 19.0.0
- affected 19.1.0
- affected 18.4.302
- affected 18.4.303
- affected 19.2.097
- affected 19.2.098
- affected 17.2.10
- affected 18.3.6.1
- affected 19.0.1a
- affected 18.2.0
- affected 18.4.3
- affected 18.4.1
- affected 17.2.8
- affected 18.3.3.1
- affected 18.4.0
- affected 18.3.1
- affected 17.2.6
- affected 17.2.9
- affected 18.3.4
- affected 17.2.5
- affected 18.3.1.1
- affected 18.3.5
- affected 18.4.0.1
- affected 18.3.3
- affected 17.2.7
- affected 17.2.4
- affected 18.3.0
- and 375 more
What to do
Exploitation: In September 2026, the Cisco PSIRT became aware of active exploitation of this vulnerability. Cisco strongly recommends that customers upgrade to a fixed software release to remediate this vulnerability.
References
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- CISA KEV catalog (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-89950 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-76504)Record last updated .