medium4.3
CVE-2026-61911
An issue was discovered in Cyrus IMAP before 3.12.4.
Impact
An issue was discovered in Cyrus IMAP before 3.12.4. There is a 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.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Cyrus | Imap | before 3.8.8 from 3.9.0 before 3.10.4 from 3.11.0 before 3.12.4 |