synced 3 MIN AGO
01 Record

CVE-2026-33263

When mail_max_userip_connections is set (default 10) and reached, submission-login can crash with epoll() panic caused by file descriptor handling issues. If running in high-security mode (default for

MediumPUBLISHEDCNA: OX
CNA base score4.3 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
View raw JSON

02 Description

When mail_max_userip_connections is set (default 10) and reached, submission-login can crash with epoll() panic caused by file descriptor handling issues. If running in high-security mode (default for

03 Exploitation and scoring

Exploitation
Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
SSVC decision
  • ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
  • AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.55% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 45.9% of scored records. A rank, not a probability.
NVD base score
4.3 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
NVD analysis status
Deferred. NVD last modified this record on 2026-09-03.
Red Hat severity
Important. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2026-08-28 10:12Z2 MO AGO
Last updated
2026-08-28 15:55Z2 MO AGO
Reserved
2026-03-18
Assigning CNA
OX
Record state
PUBLISHED
Severity
Medium (CVSS 4.3)
CNA CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Weaknesses
  • CWE-403Exposure of File Descriptor to Unintended Control Sphere ('File Descriptor Leak')Base
  • CWE-910Use of Expired File DescriptorBase
Data version
5.2
Document digest
e2c3e5eca1f7b5a3f4759821a9c6ac31247d42a3d330b67dda409cbe7d402b9a

05 Affected products

VendorProductVersionsPlatforms
Open-Xchange GmbHOX Dovecot Pro2.3.0 to < 2.3.22.2, 3.0.0 to < 3.0.7, 3.1.0 to < 3.1.6—
Open-Xchange GmbHOX Dovecot CE2.3.0 to < 2.4.5—

06 References

07 Fixed in

AlmaLinux 8

  • dovecot
    Fixed in 1:2.3.16-16.el8_10
  • dovecot-devel
    Fixed in 1:2.3.16-16.el8_10
  • dovecot-mysql
    Fixed in 1:2.3.16-16.el8_10
  • dovecot-pgsql
    Fixed in 1:2.3.16-16.el8_10
  • dovecot-pigeonhole
    Fixed in 1:2.3.16-16.el8_10

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

AlmaLinux 9

  • dovecot
    Fixed in 1:2.3.16-18.el9_8.8
  • dovecot-devel
    Fixed in 1:2.3.16-18.el9_8.8
  • dovecot-mysql
    Fixed in 1:2.3.16-18.el9_8.8
  • dovecot-pgsql
    Fixed in 1:2.3.16-18.el9_8.8
  • dovecot-pigeonhole
    Fixed in 1:2.3.16-18.el9_8.8

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

AlmaLinux 10

  • dovecot
    Fixed in 1:2.3.21-19.el10_2.8
  • dovecot-devel
    Fixed in 1:2.3.21-19.el10_2.8
  • dovecot-mysql
    Fixed in 1:2.3.21-19.el10_2.8
  • dovecot-pgsql
    Fixed in 1:2.3.21-19.el10_2.8
  • dovecot-pigeonhole
    Fixed in 1:2.3.21-19.el10_2.8

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 8

  • dovecot
    Fixed in 1:2.3.16-16.el8_10
  • dovecot-devel
    Fixed in 1:2.3.16-16.el8_10
  • dovecot-mysql
    Fixed in 1:2.3.16-16.el8_10
  • dovecot-pgsql
    Fixed in 1:2.3.16-16.el8_10
  • dovecot-pigeonhole
    Fixed in 1:2.3.16-16.el8_10

Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 9

  • dovecot
    Fixed in 1:2.3.16-18.el9_8.8
  • dovecot-devel
    Fixed in 1:2.3.16-18.el9_8.8
  • dovecot-mysql
    Fixed in 1:2.3.16-18.el9_8.8
  • dovecot-pgsql
    Fixed in 1:2.3.16-18.el9_8.8
  • dovecot-pigeonhole
    Fixed in 1:2.3.16-18.el9_8.8

Derived from AlmaLinux 9. Partial coverage: only packages taken from AlmaLinux 9 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 10

  • dovecot
    Fixed in 1:2.3.21-19.el10_2.8
  • dovecot-devel
    Fixed in 1:2.3.21-19.el10_2.8
  • dovecot-mysql
    Fixed in 1:2.3.21-19.el10_2.8
  • dovecot-pgsql
    Fixed in 1:2.3.21-19.el10_2.8
  • dovecot-pigeonhole
    Fixed in 1:2.3.21-19.el10_2.8

Derived from AlmaLinux 10. Partial coverage: only packages taken from AlmaLinux 10 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

Debian 12

  • dovecot
    No fix yet

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

  • dovecot
    Fixed in 1:2.4.1+dfsg1-6+deb13u7

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

  • dovecot
    Fixed in 1:2.4.5+dfsg1-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 16.04 LTS

  • dovecot
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 18.04 LTS

  • dovecot
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 20.04 LTS

  • dovecot
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 22.04 LTS

  • dovecot
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 24.04 LTS

  • dovecot
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 26.04 LTS

  • dovecot
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 14.04 LTS

  • dovecot
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.