CVE-2026-42844
Getgrav Grav 2.0.0
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-2026-42844 is a high-severity Improper Privilege Management (CWE-269) vulnerability in Getgrav Grav. Its CVSS base score is 8.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Abuse Elevation Control Mechanism (T1548); ranked at the 26th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to AC-2 (Account Management) and AC-24 (Access Control Decisions) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-29857
Vulnerability Data
Grav is a file-based Web platform. In Grav 2.0.0-beta.2, a low-privileged authenticated API user with api.media.write can abuse /api/v1/blueprint-upload to write an arbitrary YAML file into user/accounts/, then log in as the newly created account with api.super privileges. This results…
more
in full administrative compromise of the Grav API. This vulnerability is fixed in API 1.0.0-beta.17.
- 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 · 5 OS baselines
V5.1.1
Mitigating Controls (NIST 800-53 r5) AI
Account management directly governs assignment and tracking of privileges so proper implementation stops the weakness from being introduced.
Requiring explicit access-control decisions ensures privileges are evaluated rather than assumed or omitted.
Access enforcement applies the correct privilege checks at every request, structurally preventing unintended spheres of control.
Separation of duties constrains how privileges may be assigned, reducing the chance of overly broad actor control.
Least privilege is the direct countermeasure to improper privilege management; implementing it eliminates the root cause.
Malicious-code protection at entry points blocks dangerous file types from being accepted and executed.
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.
PR.AA-05 enforces least privilege/SoD and periodic reviews that directly remove most privilege-assignment defects, yet CWE-269 also covers escalation paths and role design outside a single access-management control.
Restricting execution of unauthorized software directly blocks dangerous uploaded files from running.
PR.AA-01 supplies credential/identity lifecycle support that can reduce some privilege-assignment errors but does not itself assign, modify, or check privileges, leaving most of CWE-269's risk unaddressed.
Config baselines and default reviews can enforce some privilege-related settings (one facet) but do not address code-level assignment/tracking logic that defines CWE-269.
Secure development practices include input validation and file-type restrictions that prevent this weakness.
PR.DS-10 protects data-in-use without touching privilege assignment/tracking, so it neither prevents CWE-269 nor removes more than one narrow facet of its risk.
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 owner approval, segregation of duties, and periodic reviews prevents the assignment of excessive or unnecessary privileges to users or processes.
Enforcing minimum-necessary privileges, temporary grants, and separation of administrative versus normal identities prevents the over-assignment of rights that CWE-269 describes.
Configuration and acceptance testing verify that file-upload handling enforces allowed types and does not permit dangerous content to be stored or executed.
Dynamic techniques that grant the minimum necessary rights for a given time window and revoke them afterward reduce the window in which excessive or unnecessary privileges can be exploited.
Explicit restrictions on privileged access and segregation of duties limit the scope of privileges that can be assigned, reducing the chance that excessive or unnecessary privileges are granted to entities.
Defining and communicating authorization levels for each role limits the assignment of excessive or unnecessary privileges.
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).
Windows 10 (1 rule)
- V-220712 Only accounts responsible for the administration of a system must have Administrator rights on the system. prevents CWE-269
Windows 11 (1 rule)
- V-253269 Only accounts responsible for the administration of a system must have Administrator rights on the system. prevents CWE-269
Windows Server 2016 (1 rule)
- V-225007 Only administrators responsible for the member server or standalone or nondomain-joined system must have Administrator rights on the system. prevents CWE-269
Windows Server 2019 (1 rule)
- V-205746 Windows Server 2019 must only allow Administrators responsible for the member server or standalone or nondomain-joined system to have Administrator rights on the system. prevents CWE-269
Windows Server 2022 (1 rule)
- V-254428 Windows Server 2022 must only allow administrators responsible for the member server or standalone or nondomain-joined system to have Administrator rights on the system. prevents CWE-269