Bug 2476476 (CVE-2026-42006) - CVE-2026-42006 dovecot: Dovecot: Denial of Service via excessive IMAP bracing
Summary: CVE-2026-42006 dovecot: Dovecot: Denial of Service via excessive IMAP bracing
Keywords:
Status: NEW
Alias: CVE-2026-42006
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 2492898 2492900 2492907 2492908 2492895 2492906
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-05-12 14:02 UTC by OSIDB Bzimport
Modified: 2026-07-23 10:23 UTC (History)
2 users (show)

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

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2026:41905 0 None None None 2026-07-20 05:09:14 UTC
Red Hat Product Errata RHSA-2026:41988 0 None None None 2026-07-20 13:01:53 UTC
Red Hat Product Errata RHSA-2026:42091 0 None None None 2026-07-20 18:13:23 UTC
Red Hat Product Errata RHSA-2026:44355 0 None None None 2026-07-23 10:23:19 UTC
Red Hat Product Errata RHSA-2026:44357 0 None None None 2026-07-23 10:16:55 UTC
Red Hat Product Errata RHSA-2026:44373 0 None None None 2026-07-23 10:22:18 UTC

Description OSIDB Bzimport 2026-05-12 14:02:24 UTC 
An attacker can cause uncontrolled memory usage with excessive bracing over IMAP. The fix in CVE-2026-27857 was incomplete, only blocking one way of doing this, so there was still another way left open. In particular, the fix was for closing braces, but you could still use open braces to bypass the limit. Using excessive bracing, attacker can cause memory usage up to configured memory limit. Install fixed version, or configure vsz_limit for imap process to low value. No publicly available exploits are known.
Comment 3 errata-xmlrpc 2026-07-20 05:09:13 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:41905 https://access.redhat.com/errata/RHSA-2026:41905
Comment 4 errata-xmlrpc 2026-07-20 13:01:53 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:41988 https://access.redhat.com/errata/RHSA-2026:41988
Comment 5 errata-xmlrpc 2026-07-20 18:13:22 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10.0 Extended Update Support

Via RHSA-2026:42091 https://access.redhat.com/errata/RHSA-2026:42091
Comment 6 errata-xmlrpc 2026-07-23 10:16:53 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions

Via RHSA-2026:44357 https://access.redhat.com/errata/RHSA-2026:44357
Comment 7 errata-xmlrpc 2026-07-23 10:22:17 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

Via RHSA-2026:44373 https://access.redhat.com/errata/RHSA-2026:44373
Comment 8 errata-xmlrpc 2026-07-23 10:23:19 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

Via RHSA-2026:44355 https://access.redhat.com/errata/RHSA-2026:44355
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