Description
An issue was discovered in cyrus-imapd in Cyrus IMAP through 3.12.2. There is heap exposure in nested MIME comment parsing. An authenticated IMAP user could craft an email message containing an RFC 822 comment ending with a backslash. When parsing the message, the server would read past the message's end in memory, and read into the heap, returning the read content to the user.
References2
Metrics
- CVSS 3.1
-
3.1
LOW
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N - EPSS — exploit probability
- 0% percentile: 19 · as of 15 November 2026
- CWE
- CWE-126
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.