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).
CVE-2026-43639
This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 0.6%, top 55% of all CVEs by exploit prediction. GitHub Security Advisory enrichment pending alignment with NVD CVSS.
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 9.1
- EG Score
- 9.1(medium)
- EG Risk
- 57(Track*)EG Risk 57/100SSVC: Track*
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity91% × 45%Exploitation40% × 40%Automatability0% × 15%Action: Watch closely — could escalate to Attend. - EPSS PROB
- 1%
- EPSS %ILE
- 45%
- KEV
- Not listed
Published
May 11, 2026
Last Modified
July 14, 2026
Advisory Details (5)
Auto-updated Aug 1, 2026Bitwarden Server < 2026.4.0 Missing Authorization via Provider Clients | Advisories | VulnCheck
https://www.vulncheck.com/advisories/bitwarden-server-missing-authorization-via-provider-clientsSanjok Karki | Offensive Security Engineer
https://sanjokkarki.com.np/blog/bitwarden-provider-takeoverVersion 2026.4.0
Patch available: bitwarden/server v2026.4.0
https://github.com/bitwarden/server/releases/tag/v2026.4.0[PM-34462] Improve role handling in provider controllers
Patch available: bitwarden/server v2026.4.0 (PR #7372 merged 2026-04-01)
https://github.com/bitwarden/server/pull/7372commit 0918bfdda6f5 (bitwarden/server)
Patch available: bitwarden/server v2026.4.0 (contains commit 0918bfdda6f5)
https://github.com/bitwarden/server/commit/0918bfdda6f5eec391c69bd9074f6aef4eac0b1dWeakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 16× in last 7d / 43× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
Showing the most recent 100 of 136 total refreshes for this CVE.
- 2026-08-03 04:19 UTCGHSA enrichment
- 2026-08-03 00:38 UTCGHSA enrichment
- 2026-08-02 20:36 UTCGHSA enrichment
- 2026-08-02 16:55 UTCGHSA enrichment
- 2026-08-02 13:14 UTCGHSA enrichment
- 2026-08-02 09:33 UTCGHSA enrichment
- 2026-08-02 05:13 UTCEG score recompute
- 2026-08-02 05:13 UTCGHSA enrichment
- 2026-08-02 02:27 UTCEPSS rescore
- 2026-08-02 01:32 UTCEG score recompute
- 2026-08-02 01:32 UTCGHSA enrichment
- 2026-08-01 04:16 UTCEPSS rescore
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- 2026-07-23 03:14 UTCEG score recompute▲ 1.10
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:24 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
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- 2026-07-19 14:31 UTCEPSS rescore
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- 2026-07-16 03:23 UTCOSV refresh
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 02:00 UTCEPSS rescore
- 2026-07-14 21:22 UTCNVD updateCVSS v3 → 9.1 · severity → CRITICAL
- 2026-07-13 22:30 UTCEPSS rescore
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- 2026-06-28 03:21 UTCGHSA enrichment
- 2026-06-27 09:46 UTCGHSA enrichment
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- 2026-06-26 21:05 UTCGHSA enrichment
- 2026-06-26 04:55 UTCGHSA enrichment
- 2026-06-25 13:49 UTCEPSS rescore
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- 2026-06-23 21:33 UTCEPSS rescore
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- 2026-06-17 17:53 UTCEPSS rescore
- 2026-06-17 00:58 UTCGHSA enrichment
- 2026-06-16 17:52 UTCEPSS rescore
- 2026-06-16 07:21 UTCGHSA enrichment
- 2026-06-15 17:49 UTCEPSS rescore
- 2026-06-15 03:04 UTCGHSA enrichment
- 2026-06-14 14:33 UTCGHSA enrichment
- 2026-06-14 01:53 UTCGHSA enrichment
- 2026-06-13 23:00 UTCEPSS rescore
- 2026-06-13 08:07 UTCGHSA enrichment
- 2026-06-12 23:12 UTCEPSS rescore
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- 2026-06-12 18:27 UTCGHSA enrichment
- 2026-06-12 05:56 UTCGHSA enrichment
- 2026-06-11 17:25 UTCGHSA enrichment
- 2026-06-11 14:00 UTCEPSS rescore
- 2026-06-11 04:54 UTCGHSA enrichment
- 2026-06-10 22:18 UTCEPSS rescore
- 2026-06-10 16:23 UTCGHSA enrichment
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- 2026-06-10 03:52 UTCGHSA enrichment
- 2026-06-09 15:21 UTCGHSA enrichment
- 2026-06-09 02:50 UTCGHSA enrichment
- 2026-06-08 14:19 UTCGHSA enrichment
- 2026-06-08 14:17 UTCEPSS rescore
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- 2026-06-08 01:48 UTCGHSA enrichment
- 2026-06-07 15:25 UTCEPSS rescore
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- 2026-06-07 13:17 UTCGHSA enrichment
- 2026-06-07 00:44 UTCGHSA enrichment
- 2026-06-06 13:47 UTCEPSS rescore
- 2026-06-06 13:47 UTCEPSS rescore
Related CVEs(same CWE)
Same CWE
10 shownCWE-862
- CVE-2013-3960EG 9.9CRITICAL
- CVE-2015-10143EG 9.8CRITICAL
- CVE-2016-11036EG 9.8CRITICAL
- CVE-2018-11541EG 9.8CRITICAL
- CVE-2011-4183NVD 6.5EG 9.8CRITICAL
- CVE-2018-10251EG 9.8EPSS p91CRITICAL
- CVE-2018-1217EG 9.8EPSS p99CRITICAL
- CVE-2018-0015EG 9.8CRITICAL
- CVE-2017-12582EG 9.8CRITICAL
- CVE-2017-1000056EG 9.8CRITICAL
Frequently asked(5)
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Dependency Blast Radius
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