An issue was discovered in cyrus-imapd in Cyrus IMAP through 3.12.2. (CVE-2026-47088)
Description
Cyrus IMAP through version 3.12.2 contains a heap exposure vulnerability in nested MIME comment parsing. An authenticated IMAP user can craft an email with an RFC 822 comment ending with a backslash, causing the server to read beyond the message's end in memory and disclose heap contents to the user. The vulnerability has a medium severity with a CVSS score of 3.1.
CVSS v3.1
Score 3.1low
Affected software
pkg:deb/ubuntu/cyrus-imapd?arch=source&distro=esm-apps/bionicpkg:deb/ubuntu/cyrus-imapd?arch=source&distro=esm-apps/focalpkg:deb/ubuntu/cyrus-imapd?arch=source&distro=esm-apps/jammypkg:deb/ubuntu/cyrus-imapd?arch=source&distro=esm-apps/noblepkg:deb/ubuntu/cyrus-imapd?arch=source&distro=stonkingpkg:deb/ubuntu/cyrus-imapd?arch=source&distro=resoluteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-47088 describes a heap exposure vulnerability in cyrus-imapd in Cyrus IMAP versions through 3.12.2. The flaw occurs during parsing of nested MIME comments when an authenticated IMAP user sends a crafted email containing an RFC 822 comment that ends with a backslash. This causes the server to read past the end of the message in memory, leaking heap data back to the user.
Potential Impact
The vulnerability allows an authenticated IMAP user to read unintended heap memory contents by exploiting the nested MIME comment parsing flaw. This could lead to partial disclosure of sensitive information stored in the heap. There is no indication of integrity or availability impact, and no known exploits in the wild.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict IMAP user privileges as appropriate and monitor for suspicious activity related to crafted MIME comments.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-47088
- Osv Schema Version
- 1.7.0
- Ecosystems
- ["Ubuntu:Pro:18.04:LTS","Ubuntu:Pro:20.04:LTS","Ubuntu:Pro:22.04:LTS","Ubuntu:Pro:24.04:LTS","Ubuntu:26.10","Ubuntu:26.04:LTS"]
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ad3f64c2cdf04f656665857
Added to database: 10/17/2026, 22:27:24 UTC
Last enriched: 10/18/2026, 01:23:19 UTC
Last updated: 10/18/2026, 01:23:19 UTC
Views: 3
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