CVE-2026-66749Public exploitNetwork attack vector

Authenticated server crash via unchecked room lookup

Published Jul 28, 2026 · Updated Jul 28, 2026

Null dereference in Let's Chat 0.4.0 through 0.4.8 allows remote authenticated users to crash the server through a crafted room lookup. The messages:list path passes an unmatched room result to room.canJoin without checking for null, causing an uncaught TypeError in its asynchronous Mongoose callback. Any ordinary account can terminate an unsupervised process, and default self-registration exposes that gate to network-reachable attackers.

CVSS severity7.1
High
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Null dereference in Let's Chat 0.4.0 through 0.4.8 allows remote authenticated users to crash the server through a crafted room lookup. The messages:list path passes an unmatched room result to room.canJoin without checking for null, causing an uncaught TypeError in its asynchronous Mongoose callback. Any ordinary account can terminate an unsupervised process, and default self-registration exposes that gate to network-reachable attackers.

The record

CVE
CVE-2026-66749
Published
Jul 28, 2026
Updated
Jul 28, 2026
Vendor
Security Compass
Product
Let's Chat
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.4.0 <=0.4.8
  2. Affected versionversion=84981a6d2534445c00ea4e095c934e46943c0b1d <=617207ff3c0c0bf8e3c7a915bd9ec03f1dd8390c

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Security Compass · Let's Chatversion=0.4.0 <=0.4.8; version=84981a6d2534445c00ea4e095c934e46943c0b1d <=617207ff3c0c0bf8e3c7a915bd9ec03f1dd8390c

Published CVSS scores

6.5VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.1VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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