Cyrus IMAP up to 3.8.7/3.10.3/3.12.3 Mailbox Mailbox/set privileges management

Summaryinfo

A vulnerability classified as critical has been found in Cyrus IMAP up to 3.8.7/3.10.3/3.12.3. The affected element is the function Mailbox/set of the component Mailbox. This manipulation causes privileges management. The identification of this vulnerability is CVE-2026-61910. It is possible to initiate the attack remotely. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Cyrus IMAP up to 3.8.7/3.10.3/3.12.3. Affected by this vulnerability is the function Mailbox/set of the component Mailbox. The manipulation with an unknown input leads to a privileges management vulnerability. The CWE definition for the vulnerability is CWE-269. The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

An issue was discovered in Cyrus IMAP before 3.12.4. Mailbox/set let a sharee change a special-use role on shared mailboxes. An authenticated user with maySetKeywords on another user's mailbox could change that mailbox's specialuse annotation. This could allow the sharee to change the shared mailbox to perform the archived, snoozed, or other role, which might cause mail mail to be written to the shared mailbox, sharing more content than intended. (This is likely to be an unusual situation, made more unusual because if the target already has an non-shared mailbox with that role, role duplication suppression will prevent the update.)

This vulnerability is known as CVE-2026-61910 since 07/13/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1068 for this issue.

Upgrading to version 3.8.8, 3.10.4 or 3.12.4 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-75130). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Name

• Cyrus IMAP

Version

• 3.8.0
• 3.8.1
• 3.8.2
• 3.8.3
• 3.8.4
• 3.8.5
• 3.8.6
• 3.8.7
• 3.10.0
• 3.10.1
• 3.10.2
• 3.10.3
• 3.12.0
• 3.12.1
• 3.12.2
• 3.12.3

CPE 2.3info

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• 🔒
• 🔒

CPE 2.2info

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• 🔒
• 🔒

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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