CVE-2026-85602 json
Grav Form Plugin before 9.1.20 reCAPTCHA v3 Authentication Bypass
published 2026-09-04 2 mo ago modified 2026-09-08 2 mo ago also EUVD-2026-71025
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 30%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- getgrav grav-plugin-form 9.1.20
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 2 mo ago
Exploit prediction
0.36% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/getgrav/grav/security/advisories/GHSA-89j6-8h38-2cc3 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 9.3 | 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 |
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
| CNA | 4.0 | 9.3 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- getgrav grav-plugin-form
Classification
- Weakness
-
- CWE-807 Reliance on Untrusted Inputs in a Security Decision
References
-
github.com
/getgrav/grav/security/advisories/GHSA-89j6-8h38-2cc3
vendor-advisory, exploit
-
vulncheck.com
/advisories/grav-form-plugin-before-9.1.20-recaptcha-v3-authentication-bypass
third-party-advisory
Sources
- CVE List CVE-2026-85602
- NVD CVE-2026-85602
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