Forwarding information received from a host listed as a trusted proxy is not kept separate from Dovecot's own authentication fields, so a value sent by that host can be injected as an internal authentication field. Any host permitted to act as a trusted proxy can authenticate as any user without knowing that user's password. This affects deployments whose password database honours a field that permits authentication without a password. Deployments that do not configure trusted proxies are not affected. Restrict the list of trusted proxy networks to hosts that are fully under your control. Update to non-vulnerable version. No publicly available exploits are known.

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Fixes

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History

Fri, 28 Aug 2026 11:30:00 +0000

Type Values Removed Values Added
Description Forwarding information received from a host listed as a trusted proxy is not kept separate from Dovecot's own authentication fields, so a value sent by that host can be injected as an internal authentication field. Any host permitted to act as a trusted proxy can authenticate as any user without knowing that user's password. This affects deployments whose password database honours a field that permits authentication without a password. Deployments that do not configure trusted proxies are not affected. Restrict the list of trusted proxy networks to hosts that are fully under your control. Update to non-vulnerable version. No publicly available exploits are known.
Weaknesses CWE-287
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: OX

Published:

Updated: 2026-08-28T10:30:53.801Z

Reserved: 2026-04-23T11:15:21.199Z

Link: CVE-2026-42008

cve-icon Vulnrichment

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cve-icon NVD

Status : Received

Published: 2026-08-28T12:16:29.380

Modified: 2026-08-28T12:16:29.380

Link: CVE-2026-42008

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses