Bug 2526684 - CVE-2026-42008 dovecot: Dovecot: Authentication bypass via trusted proxy forwarding [fedora-all]
Summary: CVE-2026-42008 dovecot: Dovecot: Authentication bypass via trusted proxy forw...
Keywords:
Status: MODIFIED
Alias: None
Product: Fedora
Classification: Fedora
Component: dovecot
Version: rawhide
Hardware: Unspecified
OS: Unspecified
medium
medium
Target Milestone: ---
Assignee: Michal Hlavinka
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard: {"flaws": ["77e320ff-fbf9-413a-9abe-a...
Depends On:
Blocks: CVE-2026-42008
TreeView+ depends on / blocked
 
Reported: 2026-09-01 07:27 UTC by Vladimir Vasilev
Modified: 2026-09-10 05:36 UTC (History)
3 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Type: ---
Embargoed:


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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


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