CVE-2026-47082 Missing authorization in Cyrus IMAP
A user can bypass ACL restrictions to save vacation auto-reply copies into unauthorized mailboxes using the Sieve :fcc feature.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-47082?
CVE-2026-47082 is a medium-severity missing authorization vulnerability in cyrusimap Cyrus IMAP, published on 16 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
An issue was discovered in cyrus-imapd in Cyrus IMAP through 3.12.2. The vacation "fcc" feature skips the destination-mailbox ACL. A user whose vacation Sieve script used :fcc (to save a copy of the sent message) could deliver vacation auto-reply copies into any mailbox the script could name, regardless of whether the script owner had insert permissions on the destination mailbox.
Weakness: CWE-863
Which versions are affected by CVE-2026-47082?
How do I fix CVE-2026-47082?
Apply the vendor's patch.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-47082 being exploited?
There is no known exploitation of CVE-2026-47082 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-47082, GHSA-pwfr-vrq6-chw9, UBUNTU-CVE-2026-47082.