CVE-2026-16587: Auth Bypass (CVSS 4.3)

Description

The Advanced Form Integration — Connect Forms to 200+ Apps plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 2.6.0. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for authenticated attackers, with subscriber-level access and above, to overwrite the site's stored MailUp OAuth tokens in the adfoin_mailup_keys option with attacker-controlled tokens, hijacking future form-submission data to a MailUp account they control or nulling the tokens to break the integration entirely. This is exploitable by any authenticated user who can reach /wp-admin/profile.php, as admin_init fires for all logged-in users visiting any wp-admin page.

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CVSS v3.1 Score

4.3

MEDIUM

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

EPSS — Exploit Prediction

0.0022

Probability of exploitation

0.13%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-862 Missing Authorization

References

Other References

https://plugins.trac.wordpress.org/browser/advanced-form-integration/tags/2.6.0/platforms/mailup/mailup.php#L375 https://plugins.trac.wordpress.org/browser/advanced-form-integration/tags/2.6.0/platforms/mailup/mailup.php#L411 https://plugins.trac.wordpress.org/browser/advanced-form-integration/tags/2.6.0/platforms/mailup/mailup.php#L51 https://plugins.trac.wordpress.org/browser/advanced-form-integration/tags/2.6.0/platforms/mailup/mailup.php#L98 https://plugins.trac.wordpress.org/changeset?reponame=&old=3621411%40advanced-form-integration&new=3621411%40advanced-form-integration https://www.wordfence.com/threat-intel/vulnerabilities/id/af913bb1-eff6-47cd-9471-f74bafda1e52?source=cve

Frequently Asked Questions

What is CVE-2026-16587? +

The Advanced Form Integration — Connect Forms to 200+ Apps plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 2.6.0. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for authenticated attackers, with subscriber-level access and above, to overwrite the site's stored MailUp OAuth tokens in the adfoin_mailup_keys option with attacker-controlled tokens, hijacking future form-submission data to a MailUp account they control or nulling the tokens to break the integration entirely. This is exploitable by any authenticated user who can reach /wp-admin/profile.php, as admin_init fires for all logged-in users visiting any wp-admin page. It has a CVSS v3.1 base score of 4.3 (MEDIUM).

How severe is CVE-2026-16587? +

CVE-2026-16587 has a CVSS v3.1 score of 4.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0022, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-16587? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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