CVE-2026-76504
CRITICAL 9.8 KNOWN EXPLOITEDA 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.
Confirmed exploited in the wild — in CISA KEV since 2026-09-30. Patch or mitigate now.
Exploitation likelihood
1.8%chance of exploitation in 30 days · 78th percentile
Impact if exploited
9.8CVSS 3.1 · CRITICAL
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-76504/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-76504/poc.json
Weakness (CWE)
- CWE-177: Improper Handling of URL Encoding (Hex Encoding)
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Cisco | Catalyst Sd Wan Manager | < 20.9.10.1 |
| Cisco | Catalyst Sd Wan Manager | ≥ 20.12 and < 20.12.8.2 |
| Cisco | Catalyst Sd Wan Manager | ≥ 20.15 and < 20.15.6.1 |
| Cisco | Catalyst Sd Wan Manager | ≥ 20.18 and < 20.18.4.1 |
| Cisco | Catalyst Sd Wan Manager | ≥ 26.1 and < 26.1.2.1 |
| Cisco | Catalyst Sd Wan Manager | 26.2 |
All CVSS metrics
- CRITICAL 9.8 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CRITICAL 9.8 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H