CVE-2026-107585

Uncontrolled eviction in the pending sign-in tables of the REST API in Progressive Robot hMailServer 6.3.4 and 6.3.5 allows a remote unauthenticated attacker to make other users' OpenID Connect, SAML and passkey sign-ins fail. The routes that start a single sign-on and hand out a passkey sign-in challenge are reached without authentication and stored pending state in bounded tables that dropped their oldest entry when full, whoever had started it. An attacker who starts sign-ins a few times a second (about a hundred a second for passkeys) pushes every other user's pending sign-in out of the table before that user's browser returns, denying single sign-on and passkey sign-in for as long as the requests continue.

CVSS v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.6
https://gitlab.com/hmailserver/hmailserver/-/work_items/63

Configurations

No configuration.

History

08 Oct 2026, 15:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-08 15:17

Updated : 2026-10-08 21:02

NVD link : CVE-2026-107585

Mitre link : CVE-2026-107585

CVE.ORG link : CVE-2026-107585

JSON object : View

Products Affected

No product.

CWE

CWE-770

Allocation of Resources Without Limits or Throttling

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