Sources: National Vulnerability Database, CVE.org, CISA KEV, FIRST EPSS
CVE-2026-127090 Overview
Jadaptive Maverick Synergy Server before 3.0.33 and 3.1.x before 3.1.7, and Maverick Legacy Server before 1.8.1, contain an authentication bypass vulnerability in SSH public key authentication that reuses cached key authorization decisions across usernames. Attackers holding a key authorized for one account can authenticate it, then send a signed SSH_MSG_USERAUTH_REQUEST with a different username on the same connection to log in as that account.
Critical Impact
Affected Products
- Jadaptive Maverick Synergy Server: see the vendor advisory for the exact affected versions
Discovery Timeline
- 2026-11-13: CVE-2026-127090 published to the National Vulnerability Database by disclosure@vulncheck.com
- 2026-11-13: last updated in the NVD database
Technical Details for CVE-2026-127090
Vulnerability Analysis
CVE-2026-127090 is a Security Vulnerability weakness (CWE-305) in Jadaptive Maverick Synergy Server. Based on its CVSS vector, the flaw can be reached over the network, needs some level of access, and needs no user interaction.
With a CVSS base score of 8.7 and an EPSS exploitation probability of 0.76 percent, apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Root Cause
The vendor description states: Jadaptive Maverick Synergy Server before 3.0.33 and 3.1.x before 3.1.7, and Maverick Legacy Server before 1.8.1, contain an authentication bypass vulnerability in SSH public key authentication that reuses cached key authorization decisions across usernames. Attackers holding a key authorized for one account can authenticate it, then send a signed SSH_MSG_USERAUTH_REQUEST with a different username on the same connection to log in as that account.
Attack Vector
Based on the CVSS vector, the flaw can be reached over the network, needs some level of access, and needs no user interaction. Attack complexity is low complexity.
No exploitation in the wild is confirmed by CISA at the time of the last update. Check the references below for any vendor or researcher proof of concept.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Detection Methods for CVE-2026-127090
Detection Strategies
- Inventory every instance of Jadaptive Maverick Synergy Server and compare the running version with the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Run an authenticated vulnerability scan once your scanner ships a check for this CVE.
Monitoring Recommendations
- Forward Jadaptive Maverick Synergy Server application, access and audit logs to your SIEM for retrospective hunting.
- Alert on new processes, configuration changes or outbound connections from the affected service.
- Track the vendor advisory and the CISA KEV catalog for changes in exploitation status.
How to Mitigate CVE-2026-127090
Immediate Actions Required
- Apply the fixed version of Jadaptive Maverick Synergy Server named in the vendor advisory.
- Prioritize internet facing and business critical instances first.
- Rescan after the change to confirm the exposure is closed.
Patch Information
Use the fixed version listed in the vendor advisory for Jadaptive Maverick Synergy Server.
Workarounds
- If patching must wait, restrict network access to the affected service and place it behind authentication or a web application firewall rule.
CWE References
Technical References
This entry is built directly from NVD, CISA KEV and EPSS data. Verify fixed versions in the vendor advisory before you deploy.
Frequently asked questions
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