Security readout for executives and security teams
Plain-English summary
Affected Grav websites can have their reCAPTCHA v3 bot protection bypassed without authentication. An attacker can disguise a v3 response as a v2 response, avoiding v3 score and action checks. This can expose protected forms to automated submissions, spam, and related abuse. The supplied sources identify version 9.1.20 as the fix.
Executive priority
Treat this as an urgent remediation for public forms using the affected plugin and reCAPTCHA v3. Upgrade promptly, beginning with forms tied to registrations, communications, or other abuse-sensitive workflows. The critical rating supports rapid action, although the supplied evidence does not establish active exploitation or a confirmed breach.
Technical view
Grav Form plugin versions 8.0.6 through 9.1.19 choose the reCAPTCHA validation path from an attacker-controlled response-field name. Supplying a v3 token under the v2 field name invokes validation that omits the v3 score threshold and expected-action verification. This is classified as CWE-807 and requires no privileges or user interaction.
Likely exposure
Exposure is limited to sites running Grav Form plugin 8.0.6 through 9.1.19 with reCAPTCHA v3 configured. Internet-facing forms are the most likely targets. Sites using version 9.1.20 or later are outside the stated vulnerable range. The bundle does not establish how many installations meet these conditions.
Exploitation context
The bypass is remotely reachable, low complexity, and available to anonymous attackers through crafted form submissions. No exploit code or special access is described. The supplied record says this CVE is not in KEV, and the bundle provides no evidence of active exploitation; absence from KEV does not prove exploitation is not occurring.
Researcher notes
The core weakness is a trust-boundary error: untrusted field naming controls the security-validation branch. Assessment should distinguish vulnerable code presence from practical exposure by confirming both the affected version and v3 configuration. The supplied sources describe a complete v3 bot-control bypass, but do not document downstream compromise, observed attacks, or affected-installation prevalence.
Mitigation direction
- Upgrade the Grav Form plugin to version 9.1.20 or later.
- Prioritize internet-facing sites that use reCAPTCHA v3 on important forms.
- If immediate upgrading is impossible, review the vendor advisory for supported temporary protections.
- Apply additional server-side abuse controls appropriate to the affected forms.
Validation and detection
- Inventory Grav sites and record each installed Form plugin version.
- Confirm whether affected installations configure reCAPTCHA v3.
- Verify production systems report version 9.1.20 or later after upgrading.
- Review form telemetry for abnormal automation or unexpected reCAPTCHA field usage.
- Regression-test legitimate form submissions and reCAPTCHA enforcement after remediation.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-807: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-85602 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.3 (4.0)
- Known Exploited
- No
- Published
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
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
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——VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N3.91.4VulnCheckVulnerability scoring details
Base CVSS 4.0 score
9.3CriticalVector: 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
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- GitHub Security Advisory (GHSA-89j6-8h38-2cc3)CVE reference, VulnCheck · vendor-advisory
- VulnCheck Advisory: Grav Form Plugin before 9.1.20 reCAPTCHA v3 Authentication BypassCVE reference, VulnCheck · third-party-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Reliance on Untrusted Inputs in a Security Decision
Reliance on Untrusted Inputs in a Security Decision represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.