CVE-2026-61911
Publication date 9 September 2026
Last updated 11 September 2026
Ubuntu priority
Description
Sieve mailbox existence oracle: An authenticated user could install a Sieve script that probed whether another user's private mailbox existed, or read the value of shared mailbox annotations, by observing which fileinto branch fired during LMTP delivery.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| cyrus-imapd | 26.04 LTS resolute |
Needs evaluation
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy |
Needs evaluation
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
Notes
mrmajumder
Vendor patch for versions 3.8, 3.10 and 3.12 stored in the embargoed repository at fixes/cyrus-imapd/patches-<version>/CVE-2026-61911.patch. For versions older than 3.8, the 3.8 patches might need to be backported
Severity score breakdown
CVSS version: CVSS v3.0
Base score
4.3 · Medium
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N