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CVE-2026-35063 OpenPLC_V3 CVE debrief

OpenPLC_V3 contains a broken access control vulnerability in its REST API. The endpoint validates JWT presence but fails to verify the caller's role, allowing any authenticated user with role=user to delete arbitrary users (including administrators) by user ID or create new accounts with role=admin, achieving full administrative access. The vulnerability was initially published on 2025-12-11 and updated on 2026-04-09. OpenPLC_v3 is now end-of-life; users should migrate to OpenPLC Runtime v4.

Vendor
OpenPLC_V3
Product
Unknown
CVSS
HIGH 8.8
CISA KEV
Not listed in stored evidence
Original CVE published
2025-12-11
Original CVE updated
2026-04-09
Advisory published
2025-12-11
Advisory updated
2026-04-09

Who should care

Organizations operating OpenPLC_v3 in industrial control system environments, OT security teams, and asset owners managing programmable logic controller deployments.

Technical summary

The OpenPLC_V3 REST API endpoint performs JWT presence validation but omits role verification. An authenticated attacker with standard user privileges can manipulate user management endpoints to delete arbitrary accounts or create new administrative accounts, resulting in complete system compromise. The vulnerability is classified under CWE-862 (Missing Authorization).

Defensive priority

HIGH

Recommended defensive actions

  • Migrate from OpenPLC_v3 to OpenPLC Runtime v4 as OpenPLC_v3 is end-of-life
  • Implement network segmentation to restrict REST API access to authorized management hosts
  • Review and audit all user accounts for unauthorized administrative privileges
  • Apply principle of least privilege to API authentication and authorization layers
  • Monitor API access logs for anomalous user creation or deletion events

Evidence notes

Vulnerability description and remediation guidance sourced from CISA CSAF advisory ICSA-25-345-10. CVSS 3.1 vector AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H confirmed in source. CWE-862 (Missing Authorization) referenced in advisory.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-35063 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-35063

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-35063 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-35063

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source item URL

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2025/icsa-25-345-10.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-advisories/icsa-25-345-10

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/uscert/ics/alerts/ICS-ALERT-10-301-01

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/resources-tools/resources/ics-recommended-practices

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/sites/default/files/publications/Cybersecurity_Best_Practices_for_Industrial_Control_Systems.pdf

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/topics/industrial-control-systems

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-alerts/ics-alert-10-301-01

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf

    Reference

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.