CVE-2026-35063
Access Control in Openplcproject Openplc V3 Firmware
Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/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:XSummary
CVE-2026-35063 is a high-severity Missing Authorization (CWE-862) vulnerability in Openplcproject Openplc V3 Firmware. Its CVSS base score is 8.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 15th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-24 (Access Control Decisions) and AC-25 (Reference Monitor) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-35063 is a critical authorization flaw in the OpenPLC_V3 REST API endpoint. The endpoint checks only for the presence of a JSON Web Token (JWT) but fails to verify the caller's role, violating CWE-862 (Missing Authorization). This allows any authenticated user with the basic role=user to delete arbitrary users—including administrators—by specifying their user ID in the request, or to create new accounts assigned the role=admin, enabling privilege escalation to full administrative access.
The vulnerability has a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), indicating exploitation over the network with low complexity and low privileges required, without user interaction or scope changes. An attacker with valid user-level credentials can achieve complete compromise of the OpenPLC_V3 instance by elevating privileges or removing higher-privileged accounts, potentially disrupting industrial control systems relying on this PLC runtime.
Mitigation guidance is available in CISA ICS Advisory ICSA-25-345-10, accessible at https://www.cisa.gov/news-events/ics-advisories/icsa-25-345-10. The vulnerability was published on 2026-04-09T20:16:25.833.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-21035
Vulnerability Data
OpenPLC_V3 REST API endpoint checks for JWT presence but never verifies the caller's role. Any authenticated user with role=user can delete any other user, including administrators, by specifying their user ID or they can create new accounts with role=admin, escalating…
more
to full administrator access.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 5 hardening rules · 3 OS baselines
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Mitigating Controls (NIST 800-53 r5) AI
AC-3 directly requires enforcement of authorization decisions on every access request, structurally eliminating missing authorization checks.
AC-24 mandates that access control decisions are applied to each request, preventing bypass of authorization logic.
AC-25 requires a tamperproof, always-invoked reference monitor that ensures authorization checks cannot be omitted.
AC-6 reduces the set of actions reachable without proper authorization, limiting blast radius of missing checks.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Explicitly requires defining, enforcing, and reviewing authorizations and least privilege, directly preventing missing authorization checks.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Requiring authentication and credentials before any access occurs eliminates the absence of authorization checks that would otherwise allow an unauthenticated actor to reach protected resources.
Requiring formal authorization of every access request before rights are granted ensures that checks for required permissions are performed, preventing missing authorization checks from being introduced.
Mandatory authorization checks and central records of granted rights ensure that every access attempt is preceded by an explicit decision rather than relying on missing checks.
Segregating the approval of access rights from their implementation provides an independent check that reduces the impact of missing authorization checks in the resulting system configuration.
By requiring competent outsiders to verify that every function enforces the need-to-know principle, the control lowers the likelihood that missing authorization checks persist undetected.
Defining authorization responsibilities and reviewing risk-treatment progress throughout the project lifecycle catches missing authorization checks before the system is deployed.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (2 rules)
- V-248581 OL 8 must require users to provide a password for privilege escalation. prevents CWE-862
- V-252656 The OL 8 operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-862
RHEL 7 (2 rules)
- V-251704 The Red Hat Enterprise Linux operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-862
- V-204429 The Red Hat Enterprise Linux operating system must be configured so that users must provide a password for privilege escalation. prevents CWE-862