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HIGH

CVE-2026-104659

CVSS v3

7.5

HIGH

EPSS Score

—

exploit probability

CISA KEV

No

known exploited

Exploitation

—

SSVC status

Description

Missing Host header validation and missing throttling of failed administrator sign-ins in the REST API listener of Progressive Robot hMailServer 6.0.0 through 6.3.5 allow a remote attacker to brute-force the server administrator's password through the administrator's own browser by DNS rebinding. The listener, which is off by default and bound to the loopback when enabled, answered requests whatever their Host header named, and a failed sign-in with the administrator's password from the loopback

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Published
2026-10-08
Last Modified
2026-10-08

Frequently asked questions

What is CVE-2026-104659?

Missing Host header validation and missing throttling of failed administrator sign-ins in the REST API listener of Progressive Robot hMailServer 6.0.0 through 6.3.5 allow a remote attacker to brute-force the server administrator's password through the administrator's own browser by DNS rebinding. The listener, which is off by default and bound to the loopback when enabled, answered requests whatever their Host header named, and a failed sign-in with the administrator's password from the loopback

Is CVE-2026-104659 actively exploited?

Active exploitation of CVE-2026-104659 has not been confirmed.

What is the CVSS score for CVE-2026-104659?

CVE-2026-104659 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H.

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