Description
Bitwarden Server before 2026.10.1 on Entity Framework backends contains an authorization bypass vulnerability that allows organization members to add ciphers to collections they cannot edit. Attackers can call POST /api/ciphers/create, where a nulled UserId is treated as administrative, to inject vault items synced to read-only or inaccessible collections' members.
Metrics
CVSS 3.1 4.3/10
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:NWeakness enumeration
Affected software
Source: the vendor's advisory (CNA). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| bitwarden | server | < 2026.10.1 |
References
- https://abraxaslabs.tech/research/bitwarden-cipher-create-acl
- https://github.com/bitwarden/server
- https://github.com/bitwarden/server/blob/v2026.10.0/src/Api/Vault/Controllers/CiphersController.cs#L355
- https://github.com/bitwarden/server/blob/v2026.10.0/src/Infrastructure.EntityFramework/Vault/Repositories/CipherRepository.cs#L112
- https://github.com/bitwarden/server/commit/9030c42bf7d8f9ac2ff9fee85c39588d5eb81499
- https://github.com/bitwarden/server/pull/8482
- https://github.com/bitwarden/server/releases/tag/v2026.10.1
- https://www.vulncheck.com/advisories/bitwarden-server-before-2026.10.1-authorization-bypass-via-post-api-ciphers-create
Timeline
- Published
- Oct 30, 2026
- Last modified
- Oct 30, 2026
- NVD status
- Awaiting Analysis