Vaultwarden
CVE-2026-27898
MEDIUM
GHSA-w9f8-m526-h7fh
Severity by source
AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Primary rating from GitHub Advisory.
CVSS VectorGitHub Advisory
Lifecycle Timeline
3DescriptionGitHub Advisory
Vaultwarden is an unofficial Bitwarden compatible server written in Rust, formerly known as bitwarden_rs. Prior to version 1.35.4, an authenticated regular user can specify another user’s cipher_id and call "PUT /api/ciphers/{id}/partial" Even though the standard retrieval API correctly denies access to that cipher, the partial update endpoint returns 200 OK and exposes cipherDetails (including name, notes, data, secureNote, etc.). This issue has been patched in version 1.35.4.
AnalysisAI
Vaultwarden versions up to 1.35.4 is affected by authorization bypass through user-controlled key (CVSS 5.4).
Technical ContextAI
This vulnerability (CWE-639: Authorization Bypass Through User-Controlled Key) affects Vaultwarden. Vaultwarden is an unofficial Bitwarden compatible server written in Rust, formerly known as bitwarden_rs. Prior to version 1.35.4, an authenticated regular user can specify another user’s cipher_id and call "PUT /api/ciphers/{id}/partial" Even though the standard retrieval API correctly denies access to that cipher, the partial update endpoint returns 200 OK and exposes cipherDetails (including name, notes, data, secureNote, etc.). This issue has been patched in version 1.35.4.
RemediationAI
Fixed in version 1.35.4.. Restrict network access to the affected service where possible.
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Same technique Authentication Bypass
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