Open-Xchange Dovecot Pro/Dovecot CE imap-hibernate out-of-bounds

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.1$0-$5k0.68

Summaryinfo

A vulnerability identified as very critical has been detected in Open-Xchange Dovecot Pro and Dovecot CE. Affected by this vulnerability is an unknown functionality of the component imap-hibernate. The manipulation leads to out-of-bounds. This vulnerability is documented as CVE-2026-40015. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in Open-Xchange Dovecot Pro and Dovecot CE (affected version not known) and classified as very critical. This issue affects some unknown functionality of the component imap-hibernate. The manipulation with an unknown input leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

An attacker that has valid credentials can open many connections to the imap-hibernate service and send invalid commands, which can intermittently cause an out-of-bounds read and crash the process. The crash interrupts hibernated IMAP sessions handled by the affected process, which can cause degradation of service for IMAP. Disable IMAP hibernation. Update to non-vulnerable version. No publicly available exploits are known.

It is possible to read the advisory at documentation.open-xchange.com. The identification of this vulnerability is CVE-2026-40015 since 04/08/2026. The exploitation is known to be easy. The attack may be initiated remotely. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/28/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-3076). Be aware that VulDB is the high quality source for vulnerability data.

Affected

  • Open Source Dovecot

Productinfo

Type

Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.1
VulDB Meta Temp Score: 7.1

VulDB Base Score: 9.9
VulDB Temp Score: 9.9
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 4.3
CNA Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

04/08/2026 CVE reserved
08/28/2026 +142 days Advisory disclosed
08/28/2026 +0 days VulDB entry created
08/28/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: open-xchange.com

Advisory: documentation.open-xchange.com
Status: Not defined

CVE: CVE-2026-40015 (🔒)
GCVE (CVE): GCVE-0-2026-40015
GCVE (VulDB): GCVE-100-396671
CERT Bund: WID-SEC-2026-3076 - Dovecot: Mehrere Schwachstellen

Entryinfo

Created: 08/28/2026 13:43
Updated: 08/28/2026 15:44
Changes: 08/28/2026 13:43 (61), 08/28/2026 15:44 (7)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

Discussion

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