CVE-2026-61910

cyrus-imapd: cyrus-imapd: Mailbox/set let sharee change special-use role on shared mailboxes

Published Sep 9, 2026 CVSS 3.1 · 3.5 Low EPSS < 1% KEV · Not listed
Description
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.)

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Cyrus
Cyrus imap
CPEs cpe:2.3:a:cyrus:imap:*:*:*:*:*:*:*:*
Vendors & Products Cyrus
Cyrus imap
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Shared Mailbox Special-Use Role Modification via mailbox/set cyrus-imapd: cyrus-imapd: Mailbox/set let sharee change special-use role on shared mailboxes
References
Metrics threat_severity

None

threat_severity

Moderate

Type Values Removed Values Added
Title Shared Mailbox Special-Use Role Modification via mailbox/set
Type Values Removed Values Added
Description 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.)
First Time appeared Cyrusimap
Cyrusimap cyrus Imap
Weaknesses CWE-863
CPEs cpe:2.3:a:cyrusimap:cyrus_imap:*:*:*:*:*:*:*:*
Vendors & Products Cyrusimap
Cyrusimap cyrus Imap
References
Metrics cvssV3_1

{'score': 3.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Sep 14, 2026, 3:41 PM
Reserved
Jul 13, 2026, 12:00 AM
Status
Analyzed
Published
Sep 9, 2026, 8:18 PM
Modified
Sep 16, 2026, 3:24 PM
Severity
Moderate
Public date
Sep 10, 2026, 7:43 AM