CVE-2026-43640

HighPublic PoC

Published: 11 May 2026

Published

11 May 2026

Modified

16 May 2026

KEV Added

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Patch

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CVSS Score 8.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

EPSS Score 0.0010 27.3th percentile

Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-43640 is a high-severity Incorrect Implementation of Authentication Algorithm (CWE-303) vulnerability in Bitwarden Server. Its CVSS base score is 8.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Steal Application Access Token (T1528); ranked at the 27.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

Threat & Defense at a Glance

What attackers do: exploitation maps to Steal Application Access Token (T1528).

Threat & Defense Details

MITRE ATT&CK Enterprise TechniquesAI

T1528 Steal Application Access Token Credential Access

Adversaries can steal application access tokens as a means of acquiring credentials to access remote systems and resources.

attack.mitre.org →

Why these techniques?

Missing re-authentication allows an authenticated session to directly retrieve/rotate the SCIM API key (an application access token), enabling T1528.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

Bitwarden Server prior to v2026.4.1 does not require master-password re-authentication when retrieving or rotating an organization's SCIM API key, allowing an authenticated user with SCIM management privileges to obtain the key using only a valid session.

Deeper analysisAI

Automated synthesis unavailable for this CVE.