Bug 2526672 - CVE-2026-40013 dovecot: Dovecot: Denial of Service in ManageSieve service via crafted Sieve script [fedora-all]
Summary: CVE-2026-40013 dovecot: Dovecot: Denial of Service in ManageSieve service via...
Keywords:
Status: ON_QA
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": ["9f0d7519-b693-454b-bc4b-2...
Depends On:
Blocks: CVE-2026-40013
TreeView+ depends on / blocked
 
Reported: 2026-09-01 07:25 UTC by Vladimir Vasilev
Modified: 2026-09-11 02:27 UTC (History)
3 users (show)

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


Attachments (Terms of Use)

Description Vladimir Vasilev 2026-09-01 07:25:05 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 attacker that has valid credentials can submit a Sieve script containing an extreme numeric literal, which causes an out-of-bounds write when the ManageSieve service compiles the script. This causes memory corruption and an observed crash of the ManageSieve process, resulting in denial of service for script management. This might be able to be used for remote code execution. Disable the ManageSieve service if users do not need remote Sieve script management. Update to non-vulnerable version. No publicly available exploits are known.

Comment 1 Fedora Update System 2026-09-10 05:35:42 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 01:34:28 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 02:07:17 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 02:27:12 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.


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