{"id":"CVE-2026-43639","aliases":["EUVD-2026-29170","GHSA-79fq-fw2p-vq3j"],"status":"published","title":"Bitwarden Server \u003c 2026.4.0 Missing Authorization via Provider Clients","description":"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).","severity":{"version":"4.0","score":8.9,"vector":"CVSS:4.0/AV:N/AC:H/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00596,"percentile":0.48929,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-862"],"published":"2026-05-11T17:14:04Z","modified":"2026-11-09T02:47:16Z","products":[{"vendor":"bitwarden","product":"server"},{"vendor":"devolutions","product":"server"}],"references":[{"url":"https://sanjokkarki.com.np/blog/bitwarden-provider-takeover","tags":["technical-description","exploit","Exploit","Third Party Advisory","evidence"]},{"url":"https://github.com/bitwarden/server/releases/tag/v2026.4.0","tags":["release-notes","Release Notes","advisory"]},{"url":"https://github.com/bitwarden/server/pull/7372","tags":["issue-tracking","patch","Issue Tracking","Patch","fix"]},{"url":"https://github.com/bitwarden/server/commit/0918bfdda6f5eec391c69bd9074f6aef4eac0b1d","tags":["patch","Patch","fix"]},{"url":"https://www.vulncheck.com/advisories/bitwarden-server-missing-authorization-via-provider-clients","tags":["third-party-advisory","Third Party Advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43639","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-79fq-fw2p-vq3j"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43639.json","tags":["advisory"]},{"url":"https://github.com/bitwarden/server","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-43639","title":"Bitwarden Server \u003c 2026.4.0 Missing Authorization via Provider Clients","description":"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).","status":"published","published":"2026-05-11T17:14:04.552Z","modified":"2026-11-08T14:03:31.107Z","cvss":[{"version":"4.0","score":8.9,"vector":"CVSS:4.0/AV:N/AC:H/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","level":"high","assessor":"cna"},{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-862"],"updated_at":"2026-11-08T15:43:33.322657Z"}],"euvd":[{"id":"EUVD-2026-29170","description":"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).","status":"published","published":"2026-05-11T17:14:04Z","modified":"2026-11-08T14:03:31Z","cvss":[{"version":"4.0","score":8.9,"vector":"CVSS:4.0/AV:N/AC:H/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","level":"high"}],"updated_at":"2026-11-08T15:13:08.77824Z"}],"ghsa":[{"id":"GHSA-79fq-fw2p-vq3j","title":"Bitwarden Server prior to v2026.4.0 contains a missing authorization vulnerability that allows a...","description":"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).","status":"published","published":"2026-05-11T18:31:46Z","modified":"2026-05-11T18:31:59Z","cvss":[{"version":"4.0","score":8.9,"vector":"CVSS:4.0/AV:N/AC:H/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"},{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-862"],"updated_at":"2026-11-02T15:07:59.393178Z"}],"nvd":[{"id":"CVE-2026-43639","description":"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).","status":"published","published":"2026-05-11T18:16:36.97Z","modified":"2026-10-26T18:10:00.173Z","cvss":[{"version":"4.0","score":8.9,"vector":"CVSS:4.0/AV:N/AC:H/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"critical","assessor":"primary"}],"cwes":["CWE-862"],"updated_at":"2026-11-02T14:12:18.239974Z"}],"osv":[{"id":"CVE-2026-43639","title":"Bitwarden Server \u003c 2026.4.0 Missing Authorization via Provider Clients","description":"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; 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