CVE-2025-34026: Versa Concerto Improper Authentication Vulnerability

In short

Versa Concerto has a weakness classified as authentication bypass using an alternate path or channel (CWE-288). CISA added it to its Known Exploited Vulnerabilities catalog on 2026-01-22. NVD lists CVSS 4.0 at 9.2 CRITICAL.

What it is

“Versa Concerto SD-WAN orchestration platform contains an improper authentication vulnerability in the Traefik reverse proxy configuration, allowing at attacker to access administrative endpoints. The internal Actuator endpoint can be leveraged for access to heap dumps and trace logs.” — CISA KEV, retrieved 2026-11-01

“The Versa Concerto SD-WAN orchestration platform is vulnerable to an authentication bypass in the Traefik reverse proxy configuration, allowing at attacker to access administrative endpoints. The internal Actuator endpoint can be leveraged for access to heap dumps and trace logs.This issue is known to affect Concerto from 12.1.2 through 12.2.0. Additional versions may be vulnerable.” — NVD, retrieved 2026-11-01

Who is affected

Versa Concerto. NVD lists the following versions as affected:

• Versions from 11.4.0 inclusive, before 12.1.2
• Versions version 12.1.2
• Versions version 12.2.0

Exploitation status

CISA KEV added: 2026-01-22. Known ransomware campaign use: Not reported by CISA. Due date CISA set for US federal civilian agencies: 2026-02-12.

Scores

NVD CVSS 4.0: 9.2 CRITICAL; vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:L/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; source [email protected].

EPSS by FIRST: 81.78%; percentile 99.64; score date 2026-10-31. EPSS estimates the probability of exploitation in the next 30 days.

CWE: CWE-288.

Timeline

CISA required action

“Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.” — CISA KEV

What to do

• Confirm whether you run Versa Concerto and which version.
• Apply the vendor update or mitigation in the advisory.
• Follow CISA’s required action.
• Review the vendor guidance on signs of compromise.
• Track the fix through completion.

References

• Vendor Advisory: https://security-portal.versa-networks.com/emailbulletins/6830f94328defa375486ff2e
• NVD detail
• CVE.org record
• CISA KEV catalog

Sources and dates

CISA Known Exploited Vulnerabilities Catalog, version 2026.10.30; retrieved 2026-11-01. CISA KEV data: CC0 1.0. No endorsement by CISA.

NVD retrieved: 2026-11-01. This product uses the NVD API but is not endorsed or certified by the NVD.

EPSS scores by FIRST; score date 2026-10-31.