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.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
bitwarden server
Default version status: unaffected
0 to < 2026.10.1affected
pkg:github/bitwarden/serverReferences
- https://github.com/bitwarden/server/commit/9030c42bf7d8f9ac2ff9fee85c39588d5eb81499 ↗
- https://github.com/bitwarden/server/pull/8482 ↗
- https://github.com/bitwarden/server/blob/v2026.10.0/src/Infrastructure.EntityFramework/Vault/Repositories/CipherRepository.cs#L112 ↗
- https://github.com/bitwarden/server/blob/v2026.10.0/src/Api/Vault/Controllers/CiphersController.cs#L355 ↗
- https://github.com/bitwarden/server/releases/tag/v2026.10.1 ↗
- https://abraxaslabs.tech/research/bitwarden-cipher-create-acl ↗
- https://github.com/bitwarden/server ↗
- https://www.vulncheck.com/advisories/bitwarden-server-before-2026.10.1-authorization-bypass-via-post-api-ciphers-create ↗