Vulnerability · Published Sep 9, 2026 · Assigned by mitre
CVE-2026-61908
Low 3.1
In plain English
A low-severity out-of-bounds read in Cyrus IMAP from cyrusimap. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 13% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
An issue was discovered in Cyrus IMAP before 3.12.4. A JMAP email-header blob ID can reference an out-of-bounds index. An authenticated user could attempt to download a crafted JMAP blob ID of the form H<emailid>-<index>, which could read past the end of the internal blob_headers array during download, exposing adjacent heap memory.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | cyrus-imapd | no fix listed | DEBIAN-CVE-2026-61908 |
| Debian:13 | cyrus-imapd | no fix listed | DEBIAN-CVE-2026-61908 |
| Debian:14 | cyrus-imapd | 3.12.4-1 | DEBIAN-CVE-2026-61908 |
| Ubuntu:26.04:LTS | cyrus-imapd | no fix listed | UBUNTU-CVE-2026-61908 |
| Ubuntu:26.10 | cyrus-imapd | no fix listed | UBUNTU-CVE-2026-61908 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| cyrusimap | Cyrus IMAP | 0 – before 3.8.83.9.0 – before 3.10.43.11.0 – before 3.12.4 |
Weakness: CWE-125 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N