CVE-2026-39912CRITICAL 9.1EPSS p43.3%

CVE-2026-39912CVE-2026-39912

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.

Scoring

CVSS 3.19.1 (CRITICAL)
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS0.58% probability of exploitation · percentile 43.3% · 2026-06-18T12:00:27Z
Published2026-04-09
Last modified2026-04-15

Underlying weaknesses· 1

CWE-201

References

  1. https://chocapikk.com/posts/2026/xboard-v2board-account-takeover/
  2. https://github.com/cedar2025/Xboard/blob/1fe6531924cc1ec662a88b9ef725afcf78d660bc/app/Http/Controllers/V1/Passport/AuthController.php#L51
  3. https://github.com/cedar2025/Xboard/blob/1fe6531924cc1ec662a88b9ef725afcf78d660bc/app/Services/Auth/MailLinkService.php#L49
  4. https://github.com/cedar2025/Xboard/commit/121511523f04882ec0c7447acd9b8ebcb8a47957
  5. https://github.com/cedar2025/Xboard/pull/873
  6. https://github.com/v2board/v2board/blob/0ca47622a50116d0ddd7ffb316b157afb57d25e8/app/Http/Controllers/Passport/AuthController.php#L71
  7. https://github.com/v2board/v2board/pull/981
  8. https://www.vulncheck.com/advisories/v2board-xboard-authentication-token-exposure-via-loginwithmaillink

1

TypeTargetConfidenceTier
WeaknessInsertion of Sensitive Information Into Sent Datacwe-2010%live

Related by meaning· 6

Nearest entities by semantic similarity across the cs-graph corpus.

CVE
CVE-2026-37982
CVE
CVE-2026-46407
CVE
CVE-2025-71278
CVE
CVE-2026-23899
CVE
CVE-2025-70948
CVE
CVE-2026-23702
Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.