Security readout for executives and security teams
Plain-English summary
CVE-2021-26726 lets an unauthenticated attacker on a reachable adjacent network execute commands on affected Valmet DNA systems with SYSTEM privileges. This is serious for industrial operations because compromise could affect confidentiality, integrity, and availability of control-system hosts.
Executive priority
Treat this as a high-priority OT exposure issue. Prioritize asset discovery and network containment first, then coordinate vendor-approved remediation during an operationally safe maintenance window.
Technical view
The vulnerability affects a Valmet DNA service on TCP port 1517 in versions from Collection 2012 to before Collection 2021, per the provided CVE data. CVSS 3.1 is 8.8 with adjacent-network attack vector, low complexity, no privileges, no user interaction, and high impact across CIA.
Likely exposure
Exposure is most likely in OT environments running Valmet DNA Collection 2012 through pre-Collection 2021 where TCP 1517 is reachable from adjacent networks. Exact deployed subversions and network reachability need local validation.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. The risk remains high because the issue is unauthenticated remote command execution with SYSTEM privileges when the service is reachable.
Researcher notes
Evidence is limited to the CVE record, Nozomi advisory reference, and Valmet advisory page. The bundle names RCE, SYSTEM privileges, TCP 1517, and affected Collection range, but does not provide exploit details or confirmed exploitation.
Mitigation direction
- Inventory Valmet DNA systems and identify Collection versions in use.
- Review Valmet advisory guidance for the supported fixed version or vendor-approved remediation.
- Restrict TCP 1517 access to only required trusted hosts.
- Segment affected OT networks from corporate and internet-routable networks.
- Monitor TCP 1517 activity and suspicious SYSTEM-level process execution.
Validation and detection
- Confirm whether any Valmet DNA host runs Collection 2012 through pre-Collection 2021.
- Verify TCP 1517 is not reachable from untrusted or broad adjacent networks.
- Check firewall rules and OT segmentation paths to affected hosts.
- Review endpoint and network logs for unexpected command execution indicators.
- Document vendor guidance, applied fixes, and remaining compensating controls.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-209: Information exposure and cloud metadata lookup
Information exposure and SSRF weaknesses can make discovery, cloud metadata, and credential material review relevant. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-272: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-305: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-78: Command execution behavior lookup
Command injection weaknesses can lead defenders to review execution techniques and command interpreter telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-26726 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.nozominetworks.com/labs/vulnerability-advisories/cve-2021-26726/CVE reference · x_refsource_CONFIRM
- https://www.valmet.com/about-us/research-and-development/vulnerabilityadvisories/CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.