PoC Index

CVE-2026-43639

CRITICAL 9.1EPSS 0.6%

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 v4.0
8.9 HIGHCVSS: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
CVSS v3.1
9.1 CRITICALCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
CVSS v3.1
8.0 HIGHCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
EPSS
0.60% chance of exploitation in the next 30 days, 46th percentile
Published
2026-05-11
Updated
2026-07-14

Proof-of-concept exploits (1)

References

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