CVE-2026-47086

Severity: low (CVSS 3.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-16 · updated 2026-10-24
Weakness: CWE-863

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.

Affected products

cyrusimap Cyrus IMAP: before 3.12.3 — fixed in 3.12.3

How to fix

Upgrade to a fixed version: cyrusimap Cyrus IMAP 3.12.3. Check the vendor advisory for mitigations.

References

https://www.cyrusimap.org/3.12/imap/download/release-notes/3.12/x/3.12.3.html
https://www.cyrusimap.org/imap/download/release-notes/index.html

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