Is CVE-2026-66749 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-66749 being exploited in the wild.

How severe is CVE-2026-66749?

Medium severity, with a CVSS score of 6.5, published 28 July 2026.

Which products and versions are affected?

sdelements Let's Chat 0.4.0 through 0.4.8.

Is there a fix for CVE-2026-66749?

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-2026-66749 attacked?

It is attacked over the network, in a network appliance.

Am I affected by CVE-2026-66749?

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-2026-66749: sdelements Let's Chat null dereference in room lookup

CVE-2026-66749 · Severity: medium · CVSS 6.5 · Published 2026-07-28

Let's Chat, a self-hosted chat application for small teams, is vulnerable to a flaw that allows any logged-in user to crash the entire server. By sending a specially crafted request for a non-existent chat room, an attacker can force the application to shut down. This results in a complete denial of service, preventing all users from communicating until the server is manually restarted.

Quick answers

Is CVE-2026-66749 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-66749 being exploited in the wild.
How severe is CVE-2026-66749?: Medium severity, with a CVSS score of 6.5, published 28 July 2026.
Which products and versions are affected?: sdelements Let's Chat 0.4.0 through 0.4.8.
Is there a fix for CVE-2026-66749?: 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-2026-66749 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-66749?: 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

A NULL pointer dereference (CWE-476) exists in Let's Chat versions 0.4.0 through 0.4.8. The vulnerability occurs when the application processes a 'GET /messages' request with a 'room' parameter consisting of a valid 24-character hex string that does not exist in the database. Because the application fails to verify if the room lookup returned a valid object before calling methods on it, an uncaught TypeError is thrown within an asynchronous Mongoose callback. Since Express does not catch exceptions in asynchronous callbacks, the error propagates to the Node.js runtime, causing the server process to terminate. This flaw is also reachable via the socket.io interface.

Affected products

sdelements Let's Chat 0.4.0 through 0.4.8

Timeline

2026-07-28: advisory: NVD publication date

References

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