v2board / Xboard Authentication Token Exposure via loginWithMailLink_CVE-2026-39912

9.1 / 10

CRITICAL

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

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.

Basic Information

ID CVE-2026-39912

Source VulnCheck

Published Apr 9, 2026 at 18:35

Modified Apr 9, 2026 at 18:51

Affected Product

Vendor v2board

Product v2board

Version 1.6.1

Affected Versions v2board v2board 1.6.1
v2board v2board bdb10bed32c5f37df2f0872c3cb354e9b7a293bd
cedar2025 Xboard 0

CWE Classification

CWE-201

References

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    "lastseen": "",
    "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.",
    "published": "2026-04-09T18:35:35.569Z",
    "modified": "2026-04-09T18:51:49.345Z",
    "type": "cve",
    "title": "v2board / Xboard Authentication Token Exposure via loginWithMailLink",
    "source": "VulnCheck",
    "references": "https://chocapikk.com/posts/2026/xboard-v2board-account-takeover/\nhttps://github.com/v2board/v2board/pull/981\nhttps://github.com/cedar2025/Xboard/pull/873\nhttps://github.com/v2board/v2board/blob/0ca47622a50116d0ddd7ffb316b157afb57d25e8/app/Http/Controllers/Passport/AuthController.php#L71\nhttps://github.com/cedar2025/Xboard/blob/1fe6531924cc1ec662a88b9ef725afcf78d660bc/app/Services/Auth/MailLinkService.php#L49\nhttps://github.com/cedar2025/Xboard/blob/1fe6531924cc1ec662a88b9ef725afcf78d660bc/app/Http/Controllers/V1/Passport/AuthController.php#L51\nhttps://github.com/cedar2025/Xboard/commit/121511523f04882ec0c7447acd9b8ebcb8a47957\nhttps://www.vulncheck.com/advisories/v2board-xboard-authentication-token-exposure-via-loginwithmaillink",
    "id": "CVE-2026-39912",
    "bulletinFamily": "",
    "cwe": [
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    "cvelist": null,
    "sourceData": "v2board v2board 1.6.1\nv2board v2board bdb10bed32c5f37df2f0872c3cb354e9b7a293bd\ncedar2025 Xboard 0",
    "sourceHref": "",
    "cvss": {
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    "product": "v2board",
    "version": "1.6.1",
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