Cyber Resilience

CVE-2026-42843

HighPublic PoC

Published: 11 May 2026

Published
11 May 2026
Modified
27 May 2026
KEV Added
Patch
CVSS Score v3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0035 27.0th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-42843 is a high-severity Incorrect Authorization (CWE-863) vulnerability in Getgrav Grav-Plugin-Api. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 27.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

Grav API Plugin is a RESTful API for Grav CMS that provides full headless access to your site's content, media, configuration, users, and system management. Prior to 1.0.0-beta.15, an insecure direct object reference and logic flaw in the Grav API…

more

plugin (UsersController::update) allows any authenticated user with basic API access (api.access) to modify their own permission configuration. An attacker can exploit this to escalate their privileges to Super Administrator (admin.super and api.super), leading to full system compromise and potential RCE. This vulnerability is fixed in 1.0.0-beta.15.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1098 Account Manipulation Persistence
Adversaries may manipulate accounts to maintain and/or elevate access to victim systems.
Why these techniques?

IDOR/logic flaw in authenticated API endpoint enables direct privilege escalation to admin.super (T1068) via unauthorized modification of account permissions (T1098), leading to full compromise/RCE.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-42609Same vendor: Getgrav
CVE-2020-36920Shared CWE-863
CVE-2026-5712Shared CWE-863
CVE-2024-41140Shared CWE-863
CVE-2025-66297Same vendor: Getgrav
CVE-2025-66299Same vendor: Getgrav
CVE-2025-41078Shared CWE-863
CVE-2025-64421Shared CWE-863
CVE-2026-41404Shared CWE-863
CVE-2024-44305Shared CWE-863

Affected Assets

getgrav
grav-plugin-api
1.0.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-863

Periodic review and update of procedures reduces incorrect authorization implementations over time.

addresses: CWE-863

Supervision identifies cases where authorization logic incorrectly permits unauthorized actions.

addresses: CWE-863

Defining permitted attribute values and auditing modifications reduces the chance of incorrect authorization outcomes due to tampered or missing labels.

addresses: CWE-863

The authorization process and usage restrictions help prevent incorrect authorization for remote access types.

addresses: CWE-863

Establishing configuration and connection requirements helps ensure correct rather than incorrect authorization for wireless access.

addresses: CWE-863

Establishing connection authorization processes for mobile devices helps ensure authorization decisions are correctly implemented rather than incorrect.

addresses: CWE-863

Monitoring account use, notifying on changes, and reviewing accounts for compliance corrects incorrect authorization assignments.

addresses: CWE-863

Ensures authorization decisions for external system use are correctly implemented and enforced.

References