Cisco Catalyst SD-WAN Controller and Manager Authentication Bypass Vulnerability
Cisco · Catalyst SD-WAN Controller and Manager
The authentication bypass is in the peering authentication mechanism of Cisco Catalyst SD-WAN Controller (formerly vSmart), Cisco Catalyst SD-WAN Manager (formerly vManage), and Cisco Catalyst SD-WAN Validator (formerly vBond). An unauthenticated remote attacker who sends crafted requests to an affected system can log in as an internal, high-privileged, non-root user on a Controller, then use NETCONF to manipulate the SD-WAN fabric's network configuration.
A vulnerability in the peering authentication in Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, and Cisco Catalyst SD-WAN Validator, formerly SD-WAN vBond, 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.
- Exploited
- Yes, in CISA KEV
- Reports
- 0
- Tactics
- 4/15
How an attack unfolds
Based on MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. mappings. Select a step to see the evidence.Exploitation timelineDated milestones for a CVE: when it was disclosed, when exploit code became public, when exploitation was confirmed, and when threat reports named it.
First seen exploited the day it was disclosed. Public exploit code (Metasploit) was available the same day.
- DisclosedFirst seen exploitedVulnCheck KEV evidenceAdded to CISA KEVEU database agreesPublic exploit codeMetasploitday 0
CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.
MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. techniques
3 TechniqueOne specific attacker behaviour in MITRE ATT&CK, such as T1190 “Exploit Public-Facing Application”. IDs with a dot, like T1059.004, are sub-techniques., grouped by TacticThe attacker’s goal at a stage of an attack in MITRE ATT&CK, such as Initial Access or Persistence. Each technique belongs to one or more tactics. in kill-chain order, 3 cited passages 3Initial AccessTA0001
attacker logs in with internal privileged account
log in to an affected Cisco Catalyst SD-WAN Controller as an internal, high-privileged
unauthenticated remote exploit of public-facing management interface
could allow an unauthenticated, remote attacker to bypass authentication
PersistenceTA0003
gains administrative privileges via authentication bypass
obtain administrative privileges on an affected system
Detection
0 rules for this CVE · 240 general rules for its techniquesRules for this CVE
0Sigma ruleAn open, vendor-neutral detection rule for log data. Security teams convert Sigma rules into searches for their own SIEM. that reference CVE-2026-20127 directly.CVE-specific rules are not available in this build. Search SigmaHQ ↗
General rules for this CVE’s techniques
These detect the technique in general, not this specific vulnerability.
Exploit Public-Facing ApplicationT1190149 general rules
- Arcadyan Router Exploitationscriticaltest
- Citrix ADS Exploitation CVE-2020-8193 CVE-2020-8195criticaltest
- Citrix Netscaler Attack CVE-2019-19781criticaltest
- Confluence Exploitation CVE-2019-3398criticaltest
- CVE-2010-5278 Exploitation Attemptcriticaltest
- CVE-2020-0688 Exchange Exploitation via Web Logcriticaltest
- CVE-2020-10148 SolarWinds Orion API Auth Bypasscriticaltest
- CVE-2020-5902 F5 BIG-IP Exploitation Attemptcriticaltest
Valid AccountsT107856 general rules
- Win Susp Computer Name Containing Samtheadmincriticaltest
- Account Created And Deleted Within A Close Time Framehightest
- Activity From Anonymous IP Addresshightest
- Atypical Travelhightest
- Azure AD Threat Intelligencehightest
- Azure Subscription Permission Elevation Via AuditLogshightest
- External Remote SMB Logon from Public IPhightest
- Impossible Travelhightest
Account ManipulationT109835 general rules
- Password Change on Directory Service Restore Mode (DSRM) Accounthighstable
- Active Directory User Backdoorshightest
- Anomalous User Activityhightest
- AWS User Login Profile Was Modifiedhightest
- Bulk Deletion Changes To Privileged Account Permissionshightest
- Cisco Local Accountshightest
- Enabled User Right in AD to Control User Objectshightest
- ESXi Admin Permission Assigned To Account Via ESXCLIhightest
Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.
What security researchers reported
Not named in any threat report yetAlso mentioned in 50 community threat pulses (AlienVault OTX)
Weaker evidencePulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.
- Actively_Exploited_Kev | Oct 31, 202630 Oct 2026
- [ShadowBrieferFeed] Hackers Exploited Cisco SD-WAN Flaw to Plant Malware Built to Steal Encryption K30 Oct 2026
- Actively_Exploited_Kev | Oct 30, 202629 Oct 2026
- Volt Typhoon Used Covert Silent Train Network in Four Zero-Day Exploitation Campaigns28 Oct 2026
- Volt Typhoon Used Covert Silent Train Network in Four Zero-Day Exploitation Campaigns28 Oct 2026
- Actively_Exploited_Kev | Oct 29, 202628 Oct 2026
- 44 more on OTX