CVE-2026-4281Network attack vector

Unauthenticated connection hijack via unchecked OAuth flow

Published Mar 26, 2026 · Updated Mar 26, 2026

Missing authorization in FormLift for Keap (Legacy) Web Forms 7.5.21 and earlier allows remote attackers to hijack its Keap connection. The plugins_loaded connect() handler exposes a generated OAuth password in a redirect, while listen_for_tokens() accepts it without authenticating the requester before update_option() stores attacker-supplied tokens and an app domain. Triggering the OAuth flow is sufficient to redirect the plugin's API traffic to an attacker-controlled server.

CVSS severity5.3
Medium
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authorization in FormLift for Keap (Legacy) Web Forms 7.5.21 and earlier allows remote attackers to hijack its Keap connection. The plugins_loaded connect() handler exposes a generated OAuth password in a redirect, while listen_for_tokens() accepts it without authenticating the requester before update_option() stores attacker-supplied tokens and an app domain. Triggering the OAuth flow is sufficient to redirect the plugin's API traffic to an attacker-controlled server.

The record

CVE
CVE-2026-4281
Published
Mar 26, 2026
Updated
Mar 26, 2026
Vendor
Groundhogg Inc.
Product
FormLift for Keap (Legacy) Web Forms
Classifications
CWE-862, T1565.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=* <=7.5.21

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Groundhogg Inc. · FormLift for Keap (Legacy) Web Formsversion=* <=7.5.21

Published CVSS scores

5.3WordfenceCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-862Missing Authorization
T1565.001Stored Data Manipulation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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