Exploited vulnerabilities / CVE-2026-20127
Confirmed exploited · authentication bypass · Cisco Catalyst SD-WAN Controller and ManagerCVE-2026-20127
Cisco Catalyst SD-WAN Controller and Manager authentication bypass, confirmed exploited in the wild.
Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, and Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, contain an authentication bypass vulnerability could allow an unauthenticated, remote attacker to bypass authentication and obtain administrative privileges on an affected system. This vulnerability exists because the peering authentication mechanism in an affected system is not working properly. An attacker could exploit this vulnerability by sending crafted requests to an affected system. A successful exploit could allow the attacker to log in to an affected Cisco Catalyst SD-WAN Controller as an internal, high-privileged, non-root user account. Using this account, the attacker could access NETCONF, which would then allow the attacker to manipulate network configuration for the SD-WAN fabric.
| CISA's name for it | Cisco Catalyst SD-WAN Controller and Manager Authentication Bypass Vulnerability |
|---|---|
| Vendor and product | Cisco · Catalyst SD-WAN Controller and Manager |
| Type | authentication bypass · CWE-287 |
| Exploited | Confirmed by CISA listed 25 February 2026 |
| Likelihood | one of the most likely to be exploited of every vulnerability tracked |
| Deadline | 27 February 2026 · already passed |
| Used in ransomware | Not reported |
| Advisories | www.cisa.gov ↗ · www.cisa.gov ↗ · sec.cloudapps.cisco.com ↗ · nvd.nist.gov ↗ |
Three steps, in this order
Apply the vendor fix and restart the affected service.
Put the login or management interface behind a VPN or allow-list; a bypass makes passwords irrelevant.
Rotate credentials and session keys the product holds, and review accounts and configuration changes since the listing date.
| CISA's required action | Please adhere to CISA’s guidelines to assess exposure and mitigate risks associated with Cisco SD-WAN devices as outlines in CISA’s Emergency Directive 26-03 (URL listed below in Notes) and CISA’s “Hunt & Hardening Guidance for Cisco SD-WAN Devices (URL listed below in Notes). Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available. |
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Know before someone else finds it
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CVE-2026-20127 in short
Is CVE-2026-20127 being exploited?
Yes. CISA added CVE-2026-20127 to its Known Exploited Vulnerabilities catalogue on 25 February 2026, which it does only on evidence of exploitation in the wild.
What is the CISA deadline for CVE-2026-20127?
US federal agencies must remediate it by 27 February 2026. Everyone else should treat that date as the latest safe point to patch an internet-facing system.
How likely is CVE-2026-20127 to be exploited in the next 30 days?
FIRST's Exploit Prediction Scoring System gives it 88%, the 99th percentile of every CVE it scores.
How do I fix CVE-2026-20127?
Apply the vendor fix and restart the affected service. Put the login or management interface behind a VPN or allow-list; a bypass makes passwords irrelevant. Rotate credentials and session keys the product holds, and review accounts and configuration changes since the listing date.
Other Cisco vulnerabilities being exploited
| CVE | Product | Type | Listed |
|---|---|---|---|
| CVE-2026-20320 | BroadWorks | exploited vulnerability | 10 November 2026 |
| CVE-2026-76418 | Secure Firewall ASA Software and Cisco Secure FTD Software | denial of service | 29 October 2026 |
| CVE-2026-76519 | Secure Email Gateway | path traversal | 14 October 2026 |
| CVE-2026-76504 | Catalyst SD-WAN Manager | privilege escalation | 30 September 2026 |
| CVE-2026-76460 | Identity Services Engine | privilege escalation | 16 September 2026 |
| CVE-2026-76461 | Secure Email Gateway | SQL injection | 14 September 2026 |
Sources: CISA Known Exploited Vulnerabilities catalogue (released 10 November 2026) and FIRST EPSS. Page compiled automatically by SAK T.L.M, the threat-intelligence tool of SAK T.E.C, on 13 November 2026.