CVE-2026-42609Public exploitNetwork attack vector

Administrator account disruption via duplicate-username overwrite

Published May 11, 2026 · Updated May 11, 2026

Authorization bypass in Grav before 2.0.0-beta.2 allows remote authenticated users to disable administrator accounts through user creation. UserObject::save fails to reject an existing username for some storage backends and transient keys, allowing supplied metadata and permissions to replace the targeted account. Access to admin.users.create is required, and overwriting administrator accounts can eliminate management access to the CMS.

CVSS severity8.1
High
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in Grav before 2.0.0-beta.2 allows remote authenticated users to disable administrator accounts through user creation. UserObject::save fails to reject an existing username for some storage backends and transient keys, allowing supplied metadata and permissions to replace the targeted account. Access to admin.users.create is required, and overwriting administrator accounts can eliminate management access to the CMS.

The record

CVE
CVE-2026-42609
Published
May 11, 2026
Updated
May 11, 2026
Vendor
Grav
Product
Grav
Classifications
CWE-269, CWE-639, CWE-285, CWE-837, T1531
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 11, 2026CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.0.0-beta.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Grav · Gravversion=< 2.0.0-beta.2

Published CVSS scores

8.1GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-269Improper Privilege Management
CWE-639Authorization Bypass Through User-Controlled Key
CWE-285Improper Authorization
CWE-837Improper Enforcement of a Single, Unique Action
T1531Account Access Removal

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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