CVE-2025-34026: Versa Concerto Improper Authentication Vulnerability

Quick Answer

CVE-2025-34026 bypasses authentication in Concerto's Traefik reverse-proxy configuration, exposing administrative Actuator endpoints and potentially heap dumps and trace logs. For 12.1.2, verify the January 24, 2025 hotfix or later image; the version number alone is insufficient. Preserve administrative-access evidence and assess sensitive data exposure. A patch does not revoke data or credentials already disclosed.

Evidence check: Vendor evidence and unresolved limits are described below. CISA KEV catalog 2026.10.02 was checked October 2. Catalog additions, vendor publication dates and update releases are separate events. No exploit, installation or recovery test is claimed.

Context

Status At A Glance

Product scope	Versa — Concerto
CVE	CVE-2025-34026
TechGeeks response tier	P0 — confirm an exact match and act now
CISA KEV added	2026-01-22
Vendor severity	Critical (recovered Versa bulletin).
CVSS	No numerical CVSS score supplied by the recovered Versa bulletin.
Ransomware field	Unknown — this is not the same as No; CISA has not marked the field Known.
Forensic-triage field	No in the current CISA field; organizations should still investigate when exposure or evidence warrants it.
CWE	CWE-288
Federal remediation date	2026-02-12 — applies to covered federal agencies; other organizations should set a risk-based deadline.

What Happened

Concerto authentication bypass: The Traefik configuration can expose administrative endpoints, including Actuator heap dumps and trace logs. CISA records known exploitation, not its prevalence or a demonstrated compromise of every Concerto deployment.

Affected Scope

Inventory Concerto 11.4.x, 12.1.1 and the exact 12.1.2 image/hotfix date. Versa lists 12.2.1 as unaffected and says its managed-service nodes were updated or mitigated; confirm your service context instead of applying that statement to customer-managed nodes.

Match the exact edition, hardware or virtual platform, release, patch level, enabled feature, and management exposure. A product-family name alone is not enough to establish applicability.

Steps

What To Do Now

1. Confirm. Inventory every Concerto asset and record its exact version, patch level, role, relevant configuration, and exposure.
2. Preserve. Save UTC timestamps, off-device authentication, firewall, proxy, DNS, endpoint, application, and SIEM evidence before logs rotate or a disruptive change removes context.
3. Contain. Restrict unnecessary internet and management-plane access using supported controls. Follow the live advisory: Open the live Versa advisory.
4. Remediate. Confirm the exact product, release, exposure, and prerequisites against the live vendor advisory, then apply the vendor-listed update or mitigation. CISA added CVE-2025-34026 to KEV on 2026-01-22.
5. Validate. Verify the resulting version or patch level, service health, logging, expected access, an expected denial, and representative dependent workflows.
6. Escalate. If exposure overlapped the vulnerable period or evidence is suspicious, treat the system as a potential incident and follow vendor and incident-response recovery guidance.

Fixed Releases And Mitigation

Investigation And Recovery

CISA's KEV record does not mark this entry for forensic triage. That field is not proof of a clean system; consult the vendor advisory for indicators and recovery guidance.

When an attacker may have gained administrative, root, SYSTEM, identity, management-plane, or code-execution access, patching alone is not an eradication claim. Preserve evidence, scope affected accounts and downstream systems, rotate exposed credentials or certificates when justified, and rebuild from a trusted source when vendor or incident-response guidance requires it.

Notes

Exploitation Evidence

Vendor statement: The recovered bulletin says Versa had no reported exploitation and notes a public proof of concept. CISA subsequently added the CVE on January 22, 2026. Keep that vendor assessment historical; it does not override CISA's known-exploited status. The portal record timestamp is not treated as a verified advisory publication date.

CISA statement: CVE-2025-34026 was added to KEV on 2026-01-22. The ransomware field is Unknown, and the forensic-triage field is No. These are separate signals.

Validation And Boundaries

This notice does not prove that every product carrying the family name is affected, that exploitation is widespread, that a clean indicator search rules out compromise, or that a successful update restored trust. TechGeeks has not reproduced the exploit and does not replace the vendor advisory, asset inventory, vulnerability scanner, or incident-response process.

Related TechGeeks Resources

• TechGeeks Security Notice Center
• All Security Notices
• What to Do When a Device Hits CISA KEV
• Router CVE Exposure, Version, and Mitigation Checklist
• IoT Firmware Update and End-of-Support Checklist
• Live Protect and Runtime Vulnerability Shielding

References

• Versa advisory or support notice
• NVD CVE record
• CISA source

Wrap-Up

Record whether CVE-2025-34026 applies to your environment. If it does, assign an owner, preserve the change and investigation evidence, complete the vendor action, and document the validated result.

Correction policy: If a primary source changes affected versions, remediation, exploitation status, or recovery guidance, TechGeeks will update this page and its verification date.