bitwarden/server

Bitwarden Server before 2026.5.0 contains a privilege escalation vulnerability that allows authenticated Custom users with ManageUsers permission to remove Admin accounts from an organization by exploiting a missing role hierarchy check in the bulk user-remove endpoint. Attackers can supply Admin organization-user IDs in a bulk DELETE request to bypass the guard enforced on the single-user removal path, effectively removing one or more Admin accounts from an organization.

Bitwarden Server before 2026.5.0 contains a broken access control vulnerability that allows any authenticated user to access arbitrary organization billing data by supplying an arbitrary organizationId to the PreviewInvoiceController endpoints without membership or authorization checks. Attackers can exploit the missing ManageOrganizationBillingRequirement on the preview invoice endpoints to retrieve Stripe-computed tax totals, subscription status, and billing details derived from any target organization's real customer and subscription data.

Bitwarden Server before 2026.5.0 contains a JSON injection vulnerability in IntegrationTemplateProcessor.ReplaceTokens(), which substitutes user-controlled values into event-integration templates without JSON encoding. When an organization has configured an event integration whose template references a user-controlled token (such as #ActingUserName# or #UserName#, populated from a member's display name), an authenticated member can set their display name to JSON metacharacters and inject arbitrary key-value pairs into the rendered payloads delivered to webhook, SIEM, Slack, Teams, or Datadog endpoints, making injected fields indistinguishable from legitimate template output.

Bitwarden Server prior to v2026.4.1 does not require master-password re-authentication when retrieving or rotating an organization's SCIM API key, allowing an authenticated user with SCIM management privileges to obtain the key using only a valid session.

Bitwarden Server prior to v2026.4.1 contains a missing authorization vulnerability that allows any authenticated user to write ciphers into an arbitrary organization via `POST /ciphers/import-organization` by submitting an empty `collections` array, which causes the server-side permission check to be skipped.

Bitwarden Server prior to v2026.4.0 contains a missing authorization vulnerability that allows a provider service user to add an arbitrary organization to their provider via `POST /providers/{providerId}/clients/existing`, resulting in takeover of the target organization; self-hosted installations are unaffected as this endpoint is restricted to Cloud via SelfHosted(NotSelfHostedOnly = true).

Bitwarden Server 1.35.1 allows SSRF because it does not consider certain IPv6 addresses (ones beginning with fc, fd, fe, or ff, and the :: address) and certain IPv4 addresses (0.0.0.0/8, 127.0.0.0/8, and 169.254.0.0/16).

The Bitwarden server through 1.32.0 has a potentially unwanted KDF.