Bug 2526685 - CVE-2026-42391 dovecot: Dovecot: Denial of Service via IMAP ID command with excessive parameters [fedora-all]
Summary: CVE-2026-42391 dovecot: Dovecot: Denial of Service via IMAP ID command with e...
Keywords:
Status: NEW
Alias: None
Product: Fedora
Classification: Fedora
Component: dovecot
Version: rawhide
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: ---
Assignee: Michal Hlavinka
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard: {"flaws": ["586f035b-8ff0-42e3-8305-e...
Depends On:
Blocks: CVE-2026-42391
TreeView+ depends on / blocked
 
Reported: 2026-09-01 07:27 UTC by Vladimir Vasilev
Modified: 2026-09-01 07:27 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 07:27:22 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.

An unauthenticated attacker can send an IMAP ID command with a very large number of parameters before logging in, which causes memory and CPU usage to grow disproportionately. The login process can be terminated by the out-of-memory handling, which also terminates all other connections handled by the same process. This can cause degradation or denial of service for IMAP logins. Limit the number of connections handled by a single imap-login process. This has a performance impact though. Update to non-vulnerable version. No publicly available exploits are known.


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