CVE-2026-89093: Auth Bypass (CVSS 5.3)

Description

The Better Messages – Chat Rooms, Group Chat, Private Messages & AI Chat Bots plugin for WordPress is vulnerable to Information Exposure by Spoofing in all versions up to, and including, 2.15.33. This is due to the `is_ai_bot_user()` function identifying privileged internal AI bot accounts by performing a prefix check for `'ai-chat-bot-'` against a guest record's stored IP address, which is populated verbatim from the client-controlled `X-Real-IP` request header during unauthenticated guest registration. This makes it possible for unauthenticated attackers to register a guest identity that the plugin treats as its own internal AI bot, bypassing the per-room role allowlist, draft-status check, and join filters — which are all short-circuited by the bot check in `user_can_join()` and `user_can_read()` — to join administrator-restricted chat rooms, post messages into them, and read the private message history of other users.

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CVSS v3.1 Score

5.3

MEDIUM

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

EPSS — Exploit Prediction

0.0056

Probability of exploitation

0.46%

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-287 Improper Authentication

References

Other References

https://plugins.trac.wordpress.org/browser/bp-better-messages/tags/2.15.33/inc/chats.php#L2145 https://plugins.trac.wordpress.org/browser/bp-better-messages/tags/2.15.33/inc/chats.php#L2168 https://plugins.trac.wordpress.org/browser/bp-better-messages/tags/2.15.33/inc/chats.php#L2196 https://plugins.trac.wordpress.org/browser/bp-better-messages/tags/2.15.33/inc/functions.php#L4155 https://plugins.trac.wordpress.org/browser/bp-better-messages/tags/2.15.33/inc/guests.php#L311 https://plugins.trac.wordpress.org/browser/bp-better-messages/tags/2.15.33/inc/guests.php#L467 https://plugins.trac.wordpress.org/browser/bp-better-messages/tags/2.15.33/inc/guests.php#L577 https://plugins.trac.wordpress.org/changeset?old_path=bp-better-messages%2Ftags%2F2.15.33%2Finc%2Ffunctions.php&new_path=bp-better-messages%2Ftags%2F3.0.0%2Finc%2Ffunctions.php https://www.wordfence.com/threat-intel/vulnerabilities/id/df28ecd7-d463-48b7-95e6-8adc9f34d6bd?source=cve

Frequently Asked Questions

What is CVE-2026-89093? +

The Better Messages – Chat Rooms, Group Chat, Private Messages & AI Chat Bots plugin for WordPress is vulnerable to Information Exposure by Spoofing in all versions up to, and including, 2.15.33. This is due to the `is_ai_bot_user()` function identifying privileged internal AI bot accounts by performing a prefix check for `'ai-chat-bot-'` against a guest record's stored IP address, which is populated verbatim from the client-controlled `X-Real-IP` request header during unauthenticated guest registration. This makes it possible for unauthenticated attackers to register a guest identity that the plugin treats as its own internal AI bot, bypassing the per-room role allowlist, draft-status check, and join filters — which are all short-circuited by the bot check in `user_can_join()` and `user_can_read()` — to join administrator-restricted chat rooms, post messages into them, and read the private message history of other users. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2026-89093? +

CVE-2026-89093 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0056, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-89093? +

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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