What’s Vulnerable › Vulnerabilities
CVE-2026-27898: Vaultwarden: Unauthorized Access via Partial Update API on Another User’s Cipher
- Severity: medium (CVSS 5.4 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-03-04 · updated 2026-06-17
- Weakness: CWE-639
Description
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.
Affected products
- dani-garcia vaultwarden: before 1.35.4 — fixed in 1.35.4
How to fix
Upgrade to a fixed version: dani-garcia vaultwarden 1.35.4. Check the vendor advisory for mitigations.
References
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