CVE-2026-66749

HIGH
MEDIUM Priority: 0.03 BB Relevance: 64/100
Published: 2026-07-28 Modified: 2026-10-24 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Interaction

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: None
S: X
AT: None
VC: None
VI: None
VA: High

Description

Let's Chat 0.4.0 through 0.4.8 contains a null dereference vulnerability that allows authenticated attackers to crash the server by supplying a valid 24-character hex string room parameter that matches no document in the database. Attackers can send a crafted GET /messages request causing an uncaught TypeError in an asynchronous Mongoose callback that terminates the Node.js server process, with the same defect reachable through multiple code paths including the socket.io interface.

Weakness Classification (1)

Bug Bounty Relevance

64 / 100
✓ Network accessible
✓ Low complexity
✓ No user interaction

CVSS Score

7.1 / 10.0 v4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.44%
Raw Score 0.004360
Percentile 37.8%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00436
2026-10-28
0.00436

Intelligence Sources

nvd ref →