CVE-2026-47086 Missing authorization in Cyrus IMAP
Authenticated users can bypass ACLs to read mail from unauthorized mailboxes by minting URLAUTH tokens via the GENURLAUTH command.
- 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-2026-47086?
CVE-2026-47086 is a low-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. GENURLAUTH-issued tokens can bypass ACLs. Any authenticated user could mint a URLAUTH token (via the GENURLAUTH command) for any mailbox they could name, even without read access on it. This would allow reading mail from mailboxes despite having no granted permissions.
Weakness: CWE-863
Which versions are affected by CVE-2026-47086?
How do I fix CVE-2026-47086?
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-2026-47086 being exploited?
There is no known exploitation of CVE-2026-47086 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-47086, GHSA-j6pg-f6px-vgh9, UBUNTU-CVE-2026-47086.