mlogclub bbs-go up to 4.4.6 Google One Tap Authentication google_one_tap improper authentication

Summaryinfo

A vulnerability, which was classified as critical, was found in mlogclub bbs-go up to 4.4.6. This vulnerability affects unknown code of the file /api/login/google_one_tap of the component Google One Tap Authentication. Executing a manipulation can lead to improper authentication. This vulnerability is tracked as CVE-2026-111639. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability has been found in mlogclub bbs-go up to 4.4.6 and classified as critical. This vulnerability affects some unknown functionality of the file /api/login/google_one_tap of the component Google One Tap Authentication. The manipulation with an unknown input leads to a improper authentication vulnerability. The CWE definition for the vulnerability is CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

bbs-go through 4.4.6 contains an authentication bypass vulnerability in the /api/login/google_one_tap endpoint that allows remote attackers to log in as other users by submitting Google ID tokens issued to any OAuth client. Attackers operating their own Google OAuth client can capture a victim's Google-signed ID token and replay it, since the aud claim is never checked, to obtain an authenticated session as the victim's Google-linked account.

The advisory is available at hackmd.io. This vulnerability was named CVE-2026-111639 since 10/16/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 10/16/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

• mlogclub

Name

• bbs-go

Version

• 4.4.0
• 4.4.1
• 4.4.2
• 4.4.3
• 4.4.4
• 4.4.5
• 4.4.6

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CPE 2.2info

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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