3.1Low
Cyrus Imap
CVE-2026-61908
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 - , which could read past the end of the internal blob_headers array during download, exposing adjacent heap memory.
What this means for your business
- It affects Cyrus Imap. It matters if your company, or a supplier that handles your data, runs it.
- An attacker can use it remotely, over a network, with an ordinary user login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 0.2% chance of attack attempts being seen in the next 30 days, ranking above 13% of all known flaws.
What to do
- 1Check whether your company or your suppliers run Cyrus Imap, and which version. The affected versions are listed further down this page.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
Not sure if your company is exposed?
Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.
Scoring
- CVSS
- 3.1 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N- Weakness
- CWE-125
- Assigned by
- cve@mitre.org
Dates
- Published
- 2026-09-09
- Last modified
- 2026-09-16
- Sources
- NVD
Affected products
- Cyrus Imap- 3.8.8, 3.9.0 - 3.10.4, 3.11.0 - 3.12.4
As listed in the NVD configuration data. Not a statement about your estate.