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PatchSiren cyber security CVE debrief

CVE-2026-65603 getgrav CVE debrief

The Grav Login plugin (grav-plugin-login) versions <= 3.8.11 contains a high-severity privilege escalation vulnerability. The flaw exists in the authenticated profile self-update handler, which fails to strip privilege fields from user-submitted form data. This allows low-privilege authenticated users to escalate privileges to super-admin, potentially enabling admin panel access, scheduler abuse, and Twig evaluation. The vulnerability is fixed in version 3.8.12.

Vendor
getgrav
Product
grav
CVSS
HIGH 8.7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-22
Original CVE updated
2026-07-22
Advisory published
2026-07-22
Advisory updated
2026-07-22

Who should care

Administrators and users of Grav CMS with the Login plugin installed should be aware of this vulnerability. If the plugin is installed and not updated to version 3.8.12 or later, immediate action is required to prevent potential privilege escalation attacks.

Technical summary

The Grav Login plugin versions <= 3.8.11 has a privilege escalation vulnerability in the authenticated profile self-update handler (processUserProfile(), the update_user task). This handler does not properly strip privilege fields ('groups', 'access') from user-submitted form data before persisting them. When an administrator has added 'groups' and/or 'access' to plugins.login.user_registration.fields and the default 'regular'/DataUser account backend is in use, a low-privilege authenticated user can POST crafted profile form data to escalate to super-admin. This could enable admin panel access, scheduler abuse (RCE), and Twig evaluation. The vulnerability is fixed in version 3.8.12.

Defensive priority

High

Recommended defensive actions

  • Immediately update the Grav Login plugin to version 3.8.12 or later.
  • Review and restrict user privileges within the Grav CMS admin panel.
  • Monitor user account activity and profile updates.
  • Implement additional security measures such as IP restrictions and two-factor authentication for admin accounts.
  • Review compensating controls for exposed systems while remediation is scheduled and verified.
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review.
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The CVE record was published on 2026-07-22T12:18:20.683Z and was last modified on 2026-07-22T17:16:59.437Z. The NVD entry is currently Awaiting Analysis. References include vendor advisories and researcher reports.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-65603 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-65603

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-65603 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-65603

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.