{"id":"CVE-2026-43639","title":"Bitwarden Server < 2026.4.0 Missing Authorization via Provider Clients","summary":"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 t…","severity":"high","cvss":8,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-862"],"vendor":"bitwarden","product":"server","affected":["server < 2026.4.0"],"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"total","timestamp":"2026-05-11T19:12:28.484106Z"},"exploitAvailable":true,"published":"2026-05-11","updated":"2026-11-08","sourceUpdated":"2026-11-08T14:03:31.107Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-43639","references":[{"url":"https://sanjokkarki.com.np/blog/bitwarden-provider-takeover"},{"url":"https://github.com/bitwarden/server/releases/tag/v2026.4.0","label":"server 2026.4.0 Release Notes"},{"url":"https://github.com/bitwarden/server/pull/7372"},{"url":"https://github.com/bitwarden/server/commit/0918bfdda6f5eec391c69bd9074f6aef4eac0b1d"},{"url":"https://www.vulncheck.com/advisories/bitwarden-server-missing-authorization-via-provider-clients"}],"tags":["cve.org","exploit-available"],"epss":0.00596,"epssPercentile":0.48742,"ingestedAt":"2026-11-08T14:51:22.427Z","slug":"CVE-2026-43639","body":"## Overview\n\nBitwarden 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).\n\n## Affected\n\n- `server < 2026.4.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":56,"depthScoreParts":{"impact":44,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[]}