CVE-2026-47082

Severity: medium (CVSS 5.4 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. 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.

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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