CVE-2026-43912Public exploitNetwork attack vector

Cross-organization vault access via unchecked group bindings

Published May 11, 2026 · Updated May 11, 2026

Improper authorization in Vaultwarden before 1.35.5 allows remote authenticated users to read and write another organization's vault data. Group-management endpoints persist supplied membership and collection IDs without checking that each belongs to the group's organization, while authorization queries trust the resulting cross-organization links. Exploitation requires one account to be an administrator in one organization, a confirmed member in another, and to use enabled groups; it exposes ciphers and permits item updates.

CVSS severity8.7
High
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authorization in Vaultwarden before 1.35.5 allows remote authenticated users to read and write another organization's vault data. Group-management endpoints persist supplied membership and collection IDs without checking that each belongs to the group's organization, while authorization queries trust the resulting cross-organization links. Exploitation requires one account to be an administrator in one organization, a confirmed member in another, and to use enabled groups; it exposes ciphers and permits item updates.

The record

CVE
CVE-2026-43912
Published
May 11, 2026
Updated
May 11, 2026
Vendor
Dani Garcia
Product
Vaultwarden
Classifications
CWE-285, T1555
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. May 11, 2026CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.35.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Dani Garcia · Vaultwardenversion=< 1.35.5

Published CVSS scores

8.7GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-285Improper Authorization
T1555Credentials from Password Stores

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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