CriticalCVE-2025-34026

    Versa Concerto Actuator Authentication Bypass Information Leak (CVE-2025-34026)

    Published In CISA KEV since Sources: CVE.org

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    What is affected, what to do

    The Versa Concerto SD-WAN orchestration platform has an authentication bypass in its Traefik reverse proxy configuration, allowing an attacker to access administrative endpoints. The internal Actuator endpoint can be exploited to obtain heap dumps and trace logs. This issue affects Concerto versions from 12.1.2 through 12.2.0, with additional versions possibly vulnerable. Given that the vulnerability is actively exploited, an immediate update to a secure version is critical to mitigate the risks.

    The vulnerability is being actively exploited; treat it as a priority. Update concerto to version 12.1.2. Immediate actions, mitigation and detection rules are in the runbook below.

    Affected
    • Versa Concerto lte 12.1.2..12.2.0

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    9.2

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: NVD, CVSS v4

    7.5

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: CVE.org

    81.8 %

    EPSS score

    High — model estimates ≥ 50% chance of real-world exploitation within 30 days.

    Source: FIRST EPSS, percentile 99.65

    Show all metrics
    Severity
    Critical
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    234.45 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    actively exploitedSource: VulnCheck KEV (opens in a new tab) How we classify
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

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    9.2 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    7.5
    CVSS v4

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    9.2
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

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    81.8 %
    High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

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    99.65
    Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    Actively exploited
    Published
    In CISA KEV since

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    CISA assessment (SSVC)
    Exploitation: active · automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 23 January 2026
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-288

    Response and mitigation

    Why act now?

    Prioritisation rationale

    This CVE is on KEV because it is unauthenticated, network-reachable and trivially reproducible — a single HTTP request pulls a heap dump containing cleartext credentials and session tokens, which an attacker then promotes into full admin access over the SD-WAN orchestration plane. Exploitation likelihood ranks among the highest across the entire CVE corpus, so expect broad opportunistic scanning; CISA has not flagged ransomware use, but credential harvesting and lateral movement through SD-WAN tunnels into branch sites are the more plausible outcomes. For NIS2-scope operators running Versa Concerto as their central SD-WAN orchestrator, treat this as P1/critical, because a compromised orchestrator affects every managed device and therefore the network integrity of every connected site; organisations without Concerto exposure can deprioritise accordingly.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Inventory every Concerto instance (versions 11.4.0 up to and including 12.2.0) and cross-check against the Versa Networks security bulletin; apply the fixed build the vendor advisory specifies — verify the exact version string there, as CISA-KEV does not list a fully fixed build for 12.2.0.
      • Pull the management UI and Traefik reverse proxy off the public internet immediately: perimeter firewall rule restricting inbound TCP/443 and TCP/9183 (Traefik metrics) plus the Spring Boot Actuator paths to defined admin jump hosts only.
      • Explicitly block Actuator endpoints (/actuator/heapdump, /actuator/trace, /actuator/env, /actuator/mappings) in the Traefik configuration or restrict them to localhost via middleware until the patch is verified in production.
      • Assume heap-dump exposure: rotate every secret stored in Concerto — service accounts for SD-WAN devices, API tokens, database credentials, SMTP/LDAP bind passwords, JWT signing keys and session secrets.
      • Run a retroactive threat hunt across at least 90 days of Traefik access logs; on any hit, trigger the IR process per BSI 200-4 or your internal playbook and forensically preserve the Concerto instance (memory dump before any reboot).

    2. Runbook step 2

      Mitigation layers

      • Network segmentation: move the Concerto orchestrator into a dedicated management VLAN, allow access only through VPN with MFA and IP allowlisting; never expose it to branch devices via public IPs.
      • Reverse-proxy hardening: rewrite Traefik router rules so any path under /actuator, /env, /heapdump, /trace, /jolokia, /mappings is dropped by a PathPrefix deny middleware before it ever reaches the backend; chain a ForwardAuth middleware against your central IdP in front.
      • WAF/IPS signature: alert and block on GET /actuator/* from any source outside the admin allowlist; Suricata/Snort rule with content:"/actuator/heapdump"; http_uri; scoped to Concerto server IPs.
      • IAM hardening: replace shared local admin accounts in Concerto with named accounts, audit for default credentials, shorten session timeouts, enforce SSO and set expiry on all API keys.
      • Configuration baseline: in application.properties, reduce Spring Boot Actuator to management.endpoints.web.exposure.include=health,info and bind management.server.port to an internal-only port; monitor for configuration drift via CMDB or config audit.
      • Backup and recovery test: take a verified-clean snapshot of the Concerto VM before any patch deployment and dry-run the restore — if the heap dump was exfiltrated, a rebuild is safer than an in-place patch.

    3. Runbook step 3

      Detection rules

      • Web server / Traefik access log: alert on any GET with URI matching /actuator/heapdump, /actuator/trace, /actuator/env, /actuator/mappings, /actuator/loggers. Sigma shape: selection: cs-uri-stem|contains: '/actuator/' combined with sc-status: 200 and c-ip outside the admin range.
      • Zeek http.log: hunt for large response bodies (>50 MB) on /actuator/heapdump — strong indicator of a successful heap-dump download; also flag unusually high response_body_len on Concerto hosts.
      • EDR/Sysmon on the Concerto host: EID 1 (Process Create) where java spawns unexpected children (sh, curl, wget, nc); EID 3 for outbound connections from the Java process to IPs outside the branch SD-WAN scope.
      • Suricata rule idea: alert http any any -> $CONCERTO_SERVERS any (msg:"CVE-2025-34026 Actuator access"; flow:to_server,established; http.uri; content:"/actuator/"; sid:1000026; rev:1;).
      • SIEM correlation (KQL shape): WebServerLogs | where UrlPath startswith "/actuator" | where ClientIp !in (AdminAllowlist) | summarize count() by ClientIp, UrlPath, bin(TimeGenerated, 5m) — threshold at a single hit, since legitimate external Actuator traffic effectively never occurs.

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    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.

    Source: NVD (NIST), cvelistv5, CISA KEV Catalog, CVE.org (MITRE)

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    VersaConcerto
    • 12.1.2 – ≤ 12.2.0
    • —
    versa-networksconcerto
    • 12.1.2
    • 11.4.0 – < 12.1.2
    • 12.2.0
    • —
    • 12.1.2
    • —

    Vendors and products

    Weakness classes (CWE)

    • CWE-288Authentication Bypass Using an Alternate Path or Channel

      Base

      The product requires authentication, but the product has an alternate path or channel that does not require authentication.

      Entry at MITRE CWE-288

    Public exploit references

    Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

    Public exploit references
    CISA KEV CatalogCISA Known Exploited Vulnerability (opens in a new tab)cisa.govactively exploited
    Reference tagged as exploitprojectdiscovery.io (opens in a new tab)PoC (publicly reported)reported, not verified—

    References & sources

    • projectdiscovery.ioblog/versa-concerto-authentication-bypass-rceExploit, Mitigation, Exploit, Mitigation, Third-party advisory
    • cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2025-34026government-resource, US government resource
    • security-portal.versa-networks.comemailbulletins/6830f94328defa375486ff2eVendor advisory, Vendor advisory
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