Vulnerability Description
V2Board 1.6.1 through 1.7.4 and Xboard through 0.1.9 expose authentication tokens in HTTP response bodies of the loginWithMailLink endpoint when the login_with_mail_link_enable feature is active. Unauthenticated attackers can POST to the loginWithMailLink endpoint with a known email address to receive the full authentication URL in the response, then exchange the token at the token2Login endpoint to obtain a valid bearer token with complete account access including admin privileges.
CVSS Score
CRITICAL
Related Weaknesses (CWE)
References
- https://chocapikk.com/posts/2026/xboard-v2board-account-takeover/
- https://github.com/cedar2025/Xboard/blob/1fe6531924cc1ec662a88b9ef725afcf78d660b
- https://github.com/cedar2025/Xboard/blob/1fe6531924cc1ec662a88b9ef725afcf78d660b
- https://github.com/cedar2025/Xboard/commit/121511523f04882ec0c7447acd9b8ebcb8a47
- https://github.com/cedar2025/Xboard/pull/873
- https://github.com/v2board/v2board/blob/0ca47622a50116d0ddd7ffb316b157afb57d25e8
- https://github.com/v2board/v2board/pull/981
- https://www.vulncheck.com/advisories/v2board-xboard-authentication-token-exposur
FAQ
What is CVE-2026-39912?
CVE-2026-39912 is a vulnerability with a CVSS score of 9.1 (CRITICAL). V2Board 1.6.1 through 1.7.4 and Xboard through 0.1.9 expose authentication tokens in HTTP response bodies of the loginWithMailLink endpoint when the login_with_mail_link_enable feature is active. Unau...
How severe is CVE-2026-39912?
CVE-2026-39912 has been rated CRITICAL with a CVSS base score of 9.1/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-39912?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.