EUVD-2026-49876

| CVE-2026-66750 MEDIUM

Missing Authorization (CWE-862)

2026-07-28 disclosure@vulncheck.com

GHSA-mf6v-fwp6-46g3

Authentication Bypass

5.3

CVSS 4.0 · Vendor: vulncheck

Severity by source

Vendor (vulncheck) PRIMARY

5.3 MEDIUM

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/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

Primary rating from Vendor (vulncheck) · only source for this CVE.

CVSS VectorVendor: vulncheck

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Lifecycle Timeline

Analysis Generated

Jul 28, 2026 - 16:41 vuln.today

DescriptionCVE.org

Let's Chat 0.3.0 through 0.4.8 contains a broken access control vulnerability that allows authenticated attackers to download file attachments from private and password-protected rooms they are not a member of by exploiting missing room membership checks in the file retrieval route. Attackers can enumerate adjacent MongoDB ObjectIds derived from a known file ID to recover files uploaded by other users, as the GET /files/:id/:name route in app/controllers/files.js only enforces login authentication without consulting room membership or the Room.canJoin check.

AnalysisAI

Unauthorized file disclosure in Let's Chat 0.3.0 through 0.4.8 allows authenticated attackers to download file attachments from any room, including private and password-protected rooms, by exploiting missing room membership checks in the file retrieval endpoint. Attackers can enumerate likely MongoDB ObjectIds to recover files uploaded by other users, effectively bypassing all room-level access restrictions. No public exploit identified at time of analysis, but the issue is trivially exploitable due to the absence of proper authorization checks.