Medium severity · published Sep 4, 2026
CVE-2026-85602
Grav Form Plugin before 9.1.20 reCAPTCHA v3 Authentication Bypass
5.3
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 30% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
GR
grav-plugin-form · getgrav
before 9.1.20 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-85602
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-85602
github.com
https://github.com/getgrav/grav/security/advisories/GHSA-89j6-8h38-2cc3
www.vulncheck.com
https://www.vulncheck.com/advisories/grav-form-plugin-before-9.1.20-recaptcha-v3-authentication-bypass
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