CVE-2026-61911

Summary

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 Software

VendorProductVersion RangeStatus
cyrusimapCyrus IMAP0 < 3.8.8affected
cyrusimapCyrus IMAP3.9.0 < 3.10.4affected
cyrusimapCyrus IMAP3.11.0 < 3.12.4affected

Weaknesses

  • CWE-497: CWE-497 Exposure of Sensitive System Information to an Unauthorized Control Sphere

References