The Grav Form plugin (getgrav/grav-plugin-form) versions 8.0.6 through 9.1.19 select the reCAPTCHA version to validate based solely on which response field key is present in the submitted payload. On a site configured for reCAPTCHA v3, an anonymous attacker can place their v3 token under the v2 field name (g-recaptcha-response instead of token), causing validation to use the v2 branch, which never applies the score threshold or verifies the expected action. This results in a complete bypass of reCAPTCHA v3 bot protection. The issue is fixed in version 9.1.20.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact Low

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
getgrav grav unaffected
Version Status Constraints
0 affected < 9.1.20
9.1.20 unaffected —

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Project Subscriptions

Vendors Products
Getgrav Subscribe
Grav Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/getgrav/grav/security/advisories/GHSA-89j6-8h38-2cc3 cve-icon cve-icon
https://www.vulncheck.com/advisories/grav-form-plugin-before-9.1.20-recaptcha-v3-authentication-bypass cve-icon cve-icon
History

Fri, 04 Sep 2026 11:45:00 +0000

Type Values Removed Values Added
Description The Grav Form plugin (getgrav/grav-plugin-form) versions 8.0.6 through 9.1.19 select the reCAPTCHA version to validate based solely on which response field key is present in the submitted payload. On a site configured for reCAPTCHA v3, an anonymous attacker can place their v3 token under the v2 field name (g-recaptcha-response instead of token), causing validation to use the v2 branch, which never applies the score threshold or verifies the expected action. This results in a complete bypass of reCAPTCHA v3 bot protection. The issue is fixed in version 9.1.20.
Title Grav Form Plugin before 9.1.20 reCAPTCHA v3 Authentication Bypass
First Time appeared Getgrav
Getgrav grav
Weaknesses CWE-807
CPEs cpe:2.3:a:getgrav:grav:*:*:*:*:*:*:*:*
Vendors & Products Getgrav
Getgrav grav
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'}

cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-09-04T11:30:04.127Z

Reserved: 2026-09-04T11:00:28.731Z

Link: CVE-2026-85602

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-04T12:17:23.903

Modified: 2026-09-04T12:17:23.903

Link: CVE-2026-85602

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-04T12:30:17Z

Weaknesses