Bug 2444681 (CVE-2026-27898)

Summary: CVE-2026-27898 vaultwarden: Vaultwarden: Information disclosure via API partial update
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedKeywords: Security
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in Vaultwarden, an unofficial Bitwarden compatible server. An authenticated regular user can exploit this by specifying another user’s cipher identifier (cipher_id) and making a partial update request to the API. This action bypasses standard access controls, leading to the exposure of sensitive cipher details, such as names, notes, and data, belonging to other users. This vulnerability results in information disclosure.
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2444909, 2444910, 2444911, 2444912, 2444913, 2444914    
Bug Blocks:    

Description OSIDB Bzimport 2026-03-04 22:01:41 UTC
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.