Bug 2526684

Summary:	CVE-2026-42008 dovecot: Dovecot: Authentication bypass via trusted proxy forwarding [fedora-all]
Product:	[Fedora] Fedora	Reporter:	Vladimir Vasilev <vvasilev>
Component:	dovecot	Assignee:	Michal Hlavinka <mhlavink>
Status:	ON_QA ---	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	rawhide	CC:	anon.amish, bennie.joubert, mhlavink
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["77e320ff-fbf9-413a-9abe-af3149930e12"]}
Fixed In Version:		Doc Type:	---
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2525575

Description Vladimir Vasilev 2026-09-01 07:27:11 UTC

Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

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.

Comment 1 Fedora Update System 2026-09-10 05:36:13 UTC

FEDORA-2026-e8a6485109 (dovecot-2.4.5-1.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-e8a6485109

Comment 2 Fedora Update System 2026-09-11 01:34:51 UTC

FEDORA-2026-8b8efbd2b8 has been pushed to the Fedora 45 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-8b8efbd2b8`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-8b8efbd2b8

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 3 Fedora Update System 2026-09-11 02:07:38 UTC

FEDORA-2026-e8a6485109 has been pushed to the Fedora 43 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-e8a6485109`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-e8a6485109

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 4 Fedora Update System 2026-09-11 02:27:34 UTC

FEDORA-2026-2e6b786570 has been pushed to the Fedora 44 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-2e6b786570`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-2e6b786570

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.