CVE-2026-61908 PUBLISHED

Assigner: mitre
Reserved: 13.07.2026 Published: 09.09.2026 Updated: 09.09.2026

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.

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
CVSS Score: 3.1

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	Low
Privileges Required	Low	Integrity Impact	None
User Interaction	None	Availability Impact	None

CVSS 3.1

Product Status

Vendor	cyrusimap
Product	Cyrus IMAP
Versions	Default: unaffected affected from 0 to 3.8.8 (excl.) affected from 3.9.0 to 3.10.4 (excl.) affected from 3.11.0 to 3.12.4 (excl.)

References

https://cyrusimap.org
https://www.cyrusimap.org/3.12/imap/download/release-notes/3.12/x/3.12.4.html
https://www.cyrusimap.org/3.12/imap/download/release-notes/3.10/x/3.10.4.html
https://www.cyrusimap.org/3.12/imap/download/release-notes/3.8/x/3.8.8.html

Problem Types

CWE-125 Out-of-bounds Read CWE