Broken Access Control in Let's Chat by Theopaid
CVE-2026-66750

5.3MEDIUM

Key Information:

Vendor

Sdelements

Status
Lets-chat
Vendor
CVE Published:
28 July 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-66750?

The Let's Chat application versions 0.3.0 through 0.4.8 are exposed to a broken access control vulnerability that permits authenticated users to download file attachments from private and password-protected rooms they do not belong to. This vulnerability arises from insufficient checks in the file retrieval route, specifically the GET /files/:id/:name endpoint, where access is granted based solely on user authentication without verifying room membership. Consequently, attackers can exploit this flaw to enumerate file IDs and retrieve documents uploaded by other users, leading to unauthorized data exposure.

Affected Version(s)

lets-chat 0.3.0 <= 0.4.8

lets-chat 0.3.0 <= 0.4.8

lets-chat 55e8833974c83559ed2cbc12bc15febeb2466254 <= 617207ff3c0c0bf8e3c7a915bd9ec03f1dd8390c

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-66750 - Proof of Concept

References

https://github.com/theopaid/Insufficient-Access-Controls-...
technical-descriptionexploit
https://www.vulncheck.com/advisories/let-s-chat-broken-ac...
third-party-advisory

CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Theodosis Paidakis
.