CVE-2026-43639

CRITICALNVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 0.6%, top 54% of all CVEs by exploit prediction. GitHub Security Advisory enrichment pending alignment with NVD CVSS.

Triggered by: NVD CVSS baseline
Sources: epss, ghsa, nvd
Elevated
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.1Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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).

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 computed
Severity91% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
1%
EPSS %ILE
47%
KEV
Not listed

Published

May 11, 2026

Last Modified

July 14, 2026

Advisory Details (5)

Auto-updated Sep 7, 2026
Patch available. Sources: github_commit, github_pr, github_release.
generic

Bitwarden Server < 2026.4.0 Missing Authorization via Provider Clients | Advisories | VulnCheck

https://www.vulncheck.com/advisories/bitwarden-server-missing-authorization-via-provider-clients
generic

Sanjok Karki | Offensive Security Engineer

https://sanjokkarki.com.np/blog/bitwarden-provider-takeover
github_release Patch Available

Version 2026.4.0

Patch available: bitwarden/server v2026.4.0

https://github.com/bitwarden/server/releases/tag/v2026.4.0
github_pr

[PM-34462] Improve role handling in provider controllers

Fix merged in bitwarden/server PR #7372 on 2026-04-01 — awaiting tagged release

https://github.com/bitwarden/server/pull/7372
github_commit

commit 0918bfdda6f5 (bitwarden/server)

Fix landed in bitwarden/server commit 0918bfdda6f5 — awaiting tagged release

https://github.com/bitwarden/server/commit/0918bfdda6f5eec391c69bd9074f6aef4eac0b1d

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 7× in last 7d / 32× 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 241 total refreshes for this CVE.

  1. 2026-09-13 16:47 UTCEPSS rescore
  2. 2026-09-12 15:01 UTCEPSS rescore
  3. 2026-09-11 14:53 UTCEPSS rescore
  4. 2026-09-11 12:23 UTCOSV refresh
  5. 2026-09-11 09:37 UTCEPSS rescore
  6. 2026-09-10 09:34 UTCEPSS rescore
  7. 2026-09-08 22:00 UTCEPSS rescore
  8. 2026-09-07 16:01 UTCEPSS rescore
  9. 2026-09-06 13:47 UTCEPSS rescore
  10. 2026-09-04 05:06 UTCEPSS rescore
  11. 2026-09-02 14:12 UTCEPSS rescore
  12. 2026-09-01 13:54 UTCEPSS rescore
  13. 2026-08-30 19:17 UTCEPSS rescore
  14. 2026-08-30 01:22 UTCEPSS rescore
  15. 2026-08-28 21:41 UTCEPSS rescore
  16. 2026-08-27 14:25 UTCEPSS rescore
  17. 2026-08-26 14:46 UTCEPSS rescore
  18. 2026-08-25 13:49 UTCEPSS rescore
  19. 2026-08-23 18:38 UTCEG score recompute
  20. 2026-08-23 18:38 UTCGHSA enrichment
  21. 2026-08-23 00:19 UTCEPSS rescore
  22. 2026-08-21 23:49 UTCEPSS rescore
  23. 2026-08-20 22:55 UTCEPSS rescore
  24. 2026-08-19 17:04 UTCEPSS rescore
  25. 2026-08-18 13:48 UTCEPSS rescore
Show 75 more
  1. 2026-08-17 14:50 UTCEG score recompute
  2. 2026-08-17 14:50 UTCGHSA enrichment
  3. 2026-08-17 13:47 UTCEPSS rescore
  4. 2026-08-17 11:09 UTCEG score recompute
  5. 2026-08-17 11:09 UTCGHSA enrichment
  6. 2026-08-16 14:56 UTCEPSS rescore
  7. 2026-08-16 11:47 UTCGHSA enrichment
  8. 2026-08-16 08:06 UTCGHSA enrichment
  9. 2026-08-16 04:25 UTCEG score recompute
  10. 2026-08-16 04:25 UTCGHSA enrichment
  11. 2026-08-16 02:14 UTCEPSS rescore
  12. 2026-08-15 01:30 UTCEPSS rescore
  13. 2026-08-15 01:25 UTCGHSA enrichment
  14. 2026-08-14 21:42 UTCGHSA enrichment
  15. 2026-08-14 18:01 UTCGHSA enrichment
  16. 2026-08-14 14:00 UTCGHSA enrichment
  17. 2026-08-14 10:19 UTCGHSA enrichment
  18. 2026-08-14 06:38 UTCGHSA enrichment
  19. 2026-08-14 02:57 UTCEG score recompute
  20. 2026-08-14 02:57 UTCGHSA enrichment
  21. 2026-08-13 22:00 UTCEPSS rescore
  22. 2026-08-13 08:17 UTCGHSA enrichment
  23. 2026-08-13 03:32 UTCGHSA enrichment
  24. 2026-08-12 23:51 UTCGHSA enrichment
  25. 2026-08-12 20:10 UTCGHSA enrichment
  26. 2026-08-12 16:30 UTCEG score recompute
  27. 2026-08-12 16:30 UTCGHSA enrichment
  28. 2026-08-12 13:51 UTCEPSS rescore
  29. 2026-08-11 23:08 UTCGHSA enrichment
  30. 2026-08-11 19:27 UTCGHSA enrichment
  31. 2026-08-11 15:46 UTCEG score recompute
  32. 2026-08-11 15:46 UTCGHSA enrichment
  33. 2026-08-11 13:43 UTCEPSS rescore
  34. 2026-08-11 08:32 UTCGHSA enrichment
  35. 2026-08-11 04:51 UTCGHSA enrichment
  36. 2026-08-11 01:10 UTCEG score recompute
  37. 2026-08-11 01:10 UTCGHSA enrichment
  38. 2026-08-11 00:00 UTCEPSS rescore
  39. 2026-08-10 12:16 UTCGHSA enrichment
  40. 2026-08-10 08:36 UTCGHSA enrichment
  41. 2026-08-10 04:53 UTCGHSA enrichment
  42. 2026-08-10 01:12 UTCGHSA enrichment
  43. 2026-08-09 21:32 UTCGHSA enrichment
  44. 2026-08-09 17:50 UTCGHSA enrichment
  45. 2026-08-09 14:09 UTCEG score recompute
  46. 2026-08-09 14:09 UTCGHSA enrichment
  47. 2026-08-09 13:46 UTCEPSS rescore
  48. 2026-08-09 10:28 UTCGHSA enrichment
  49. 2026-08-09 05:55 UTCGHSA enrichment
  50. 2026-08-09 02:14 UTCEG score recompute
  51. 2026-08-09 02:14 UTCGHSA enrichment
  52. 2026-08-08 16:37 UTCEPSS rescore
  53. 2026-08-08 10:18 UTCGHSA enrichment
  54. 2026-08-08 06:37 UTCGHSA enrichment
  55. 2026-08-08 02:56 UTCGHSA enrichment
  56. 2026-08-07 23:15 UTCGHSA enrichment
  57. 2026-08-07 19:34 UTCEG score recompute
  58. 2026-08-07 19:34 UTCGHSA enrichment
  59. 2026-08-07 15:53 UTCGHSA enrichment
  60. 2026-08-07 12:12 UTCGHSA enrichment
  61. 2026-08-07 08:09 UTCGHSA enrichment
  62. 2026-08-07 01:37 UTCGHSA enrichment
  63. 2026-08-06 20:32 UTCGHSA enrichment
  64. 2026-08-06 16:51 UTCEG score recompute
  65. 2026-08-06 16:50 UTCGHSA enrichment
  66. 2026-08-06 13:46 UTCEPSS rescore
  67. 2026-08-06 12:41 UTCGHSA enrichment
  68. 2026-08-06 09:00 UTCGHSA enrichment
  69. 2026-08-06 05:19 UTCGHSA enrichment
  70. 2026-08-06 01:38 UTCGHSA enrichment
  71. 2026-08-05 21:57 UTCEG score recompute
  72. 2026-08-05 21:57 UTCGHSA enrichment
  73. 2026-08-05 19:17 UTCEPSS rescore
  74. 2026-08-04 15:10 UTCEPSS rescore
  75. 2026-08-04 10:38 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-43639?
CVE-2026-43639 is a critical vulnerability published on May 11, 2026. 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…
When was CVE-2026-43639 disclosed?
CVE-2026-43639 was first published in the National Vulnerability Database on May 11, 2026, with the most recent update on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-43639 actively exploited?
CVE-2026-43639 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 53.4% of all scored CVEs.
What is the CVSS score of CVE-2026-43639?
CVE-2026-43639 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-43639?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43639, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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