Open-Xchange Dovecot Pro/Dovecot CE allocation of resources

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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4.8$0-$5k2.58

Summaryinfo

A vulnerability was found in Open-Xchange Dovecot Pro and Dovecot CE. It has been rated as critical. Affected by this issue is some unknown functionality. The manipulation leads to allocation of resources. This vulnerability is listed as CVE-2026-52681. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in Open-Xchange Dovecot Pro and Dovecot CE (version unknown). It has been rated as critical. This issue affects an unknown function. The manipulation with an unknown input leads to a allocation of resources vulnerability. Using CWE to declare the problem leads to CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. Impacted is availability. The summary by CVE is:

Sieve CPU resource usage is tracked in the compiled script, so an attacker that has valid credentials can reset the accounting by repeatedly changing the active script. Compiled script files are also not removed when a script is deleted or renamed. The configured Sieve CPU limit can be bypassed, allowing sustained CPU consumption, and the leftover files increase disk consumption. Both can cause degradation of service for mail delivery. Monitor system for abnormal CPU usage and disk consumption. 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-2026-52681 since 06/08/2026. 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 attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

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). Statistical analysis made it clear that VulDB provides the best quality 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: 4.8
VulDB Meta Temp Score: 4.8

VulDB Base Score: 6.5
VulDB Temp Score: 6.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 3.1
CNA Vector: 🔒

CVSSv2info

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

Exploitinginfo

Class: Allocation of resources
CWE: CWE-770 / CWE-400 / CWE-404
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

06/08/2026 CVE reserved
08/28/2026 +81 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-2026-52681 (🔒)
GCVE (CVE): GCVE-0-2026-52681
GCVE (VulDB): GCVE-100-396683
CERT Bund: WID-SEC-2026-3076 - Dovecot: Mehrere Schwachstellen

Entryinfo

Created: 08/28/2026 13:55
Updated: 08/28/2026 19:37
Changes: 08/28/2026 13:55 (60), 08/28/2026 19:37 (7)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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