Vulnerability · Published Sep 9, 2026 · Assigned by mitre
CVE-2026-61910
Low 3.5
In plain English
A low-severity incorrect authorization in Cyrus IMAP from cyrusimap. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 9% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | cyrus-imapd | no fix listed | DEBIAN-CVE-2026-61910 |
| Debian:13 | cyrus-imapd | no fix listed | DEBIAN-CVE-2026-61910 |
| Debian:14 | cyrus-imapd | 3.12.4-1 | DEBIAN-CVE-2026-61910 |
| Ubuntu:26.04:LTS | cyrus-imapd | no fix listed | UBUNTU-CVE-2026-61910 |
| Ubuntu:26.10 | cyrus-imapd | no fix listed | UBUNTU-CVE-2026-61910 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| cyrusimap | Cyrus IMAP | 0 – before 3.8.83.9.0 – before 3.10.43.11.0 – before 3.12.4 |
Weakness: CWE-863 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N