Is CVE-2026-61908 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-61908 being exploited in the wild.

How severe is CVE-2026-61908?

Low severity, with a CVSS score of 3.1, published 9 September 2026.

Is there a fix for CVE-2026-61908?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-61908 attacked?

It is attacked over the network, in a hosted service.

Am I affected by CVE-2026-61908?

Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-61908: Cyrus IMAP JMAP email-header blob ID out-of-bounds index

CVE-2026-61908 · Severity: low · CVSS 3.1 · Published 2026-09-09

Cyrus IMAP is an open-source email, contacts, and calendar server widely used in enterprises and universities. An authenticated user can craft a malicious JMAP blob request that reads beyond the bounds of an internal array, exposing sensitive heap memory data that should remain private.

Quick answers

Is CVE-2026-61908 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-61908 being exploited in the wild.
How severe is CVE-2026-61908?: Low severity, with a CVSS score of 3.1, published 9 September 2026.
Which products and versions are affected?: Cyrus IMAP before 3.12.4.
Is there a fix for CVE-2026-61908?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-61908 attacked?: It is attacked over the network, in a hosted service.
Am I affected by CVE-2026-61908?: Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is an out-of-bounds read in the JMAP email-header blob ID handler. An authenticated attacker can craft a specially-formed blob ID of the form H<emailid>-<index> where the index parameter references an out-of-bounds memory location in the internal blob_headers array. During blob download, this causes the code to read past the end of the array, exposing adjacent heap memory. The vulnerability requires prior authentication and can be triggered via network. The fix is available in Cyrus IMAP version 3.12.4 and later.

Affected products

Cyrus IMAP before 3.12.4

Timeline

2026-09-09: disclosed

References

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