What’s Vulnerable › Vulnerabilities

CVE-2026-61910

• Severity: medium (CVSS 5.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-09 · updated 2026-09-16
• Weakness: CWE-863

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.)

Affected products

• cyrusimap Cyrus IMAP: before 3.8.8; from 3.9.0 before 3.10.4; from 3.11.0 before 3.12.4 — fixed in 3.10.4, 3.12.4, 3.8.8

How to fix

Upgrade to a fixed version: cyrusimap Cyrus IMAP 3.10.4, 3.12.4, 3.8.8. Check the vendor advisory for mitigations.

References

• https://cyrusimap.org
• https://www.cyrusimap.org/3.12/imap/download/release-notes/3.10/x/3.10.4.html
• https://www.cyrusimap.org/3.12/imap/download/release-notes/3.12/x/3.12.4.html
• https://www.cyrusimap.org/3.12/imap/download/release-notes/3.8/x/3.8.8.html

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