GravApplication · Getgrav

CVE-2026-42609

HIGH · 8.1 CVSS v3.1 Published 2026-05-11
Fix available
A fix is available. Upgrade to after 1.8.0 or later.
See remediation →
87/100
Remediation priority · High
Public exploit Remotely reachable Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Grav is a file-based Web platform. Prior to 2.0.0-beta.2, a business logic vulnerability in the Grav Admin Panel allows a low-privileged user (with only user creation permissions) to overwrite existing accounts, including the primary administrator. By creating a new user with a username that already exists, the system updates the existing account's metadata and permissions instead of rejecting the request. This leads to a Denial of Service (DoS) on administrative functions and Privilege De-escalation of the root account. This vulnerability is fixed in 2.0.0-beta.2.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-269

Privileges are granted, or fail to be dropped, incorrectly, so an action runs with more power than it should. An attacker who reaches that path inherits the excess privilege. The fix is least-privilege throughout, with explicit, checked transitions whenever privilege changes.

General guidance for the improper privilege management class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
GravApplication
Affected:<= 1.8.0= 2.0.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
High

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

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 1.8.0
Vendor patch github.com →
Recommended fix High confidence

Grav 2.0.0-beta.2 or later

  1. 1. Backup the entire Grav installation, including the /user/accounts/ directory and configuration files
  2. 2. Verify current Grav version by checking the version file or admin panel
  3. 3. Download Grav version 2.0.0-beta.2 or later from the official repository at github.com/getgrav/grav
  4. 4. Replace core files, preserving custom content in /user/ and configuration files
  5. 5. Clear any cached data by removing the /cache/ and /tmp/ directories
  6. 6. Test the user creation functionality in the admin panel to confirm the fix works
  7. 7. Verify that creating a user with an existing username now properly rejects the request instead of overwriting
Caveat Beta release may not be production-ready; test thoroughly before deploying to production environments

Generated from the published advisory — verify against the referenced sources before acting.

We can identify the exact fixed release, upgrade, and verify it in staging — typical engagement from $1,950. Get the upgrade done

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-42609 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data