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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| v2board | v2board | 1.6.1 – ≤ 1.7.4 | — |
| cedar2025 | Xboard | ≤ 0.1.9 | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 1 repository
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Chocapikk/CVE-2026-39912 ★ 2 · Apr 9, 2026
Xboard / V2Board Unauth Account Takeover - Magic Link Token Leak (CVE-2026-39912)
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
References
- https://chocapikk.com/posts/2026/xboard-v2board-account-takeover/ technical-description exploit
- https://github.com/v2board/v2board/pull/981 issue-tracking patch
- https://github.com/cedar2025/Xboard/pull/873 issue-tracking patch
- https://github.com/v2board/v2board/blob/0ca47622a50116d0ddd7ffb316b157afb57d25e8/app/Http/Controllers/Passport/AuthController.php#L71 related
- https://github.com/cedar2025/Xboard/blob/1fe6531924cc1ec662a88b9ef725afcf78d660bc/app/Services/Auth/MailLinkService.php#L49 related
- https://github.com/cedar2025/Xboard/blob/1fe6531924cc1ec662a88b9ef725afcf78d660bc/app/Http/Controllers/V1/Passport/AuthController.php#L51 related
- https://github.com/cedar2025/Xboard/commit/121511523f04882ec0c7447acd9b8ebcb8a47957 patch
- https://www.vulncheck.com/advisories/v2board-xboard-authentication-token-exposure-via-loginwithmaillink third-party-advisory