Authenticated attachment disclosure via missing room check
Published Jul 28, 2026 · Updated Jul 28, 2026
Broken access control in Let's Chat 0.3.0 through 0.4.8 allows remote authenticated users to read restricted room attachments. The GET /files/:id/:name route in app/controllers/files.js calls requireLogin and findById, then serves or redirects to the file without checking file.room or Room.canJoin. Exploitation requires an ordinary account, files.enable set to true, and a known or adjacent MongoDB ObjectId; it exposes attachment contents from private or password-protected rooms.
Summary
What happened
Broken access control in Let's Chat 0.3.0 through 0.4.8 allows remote authenticated users to read restricted room attachments. The GET /files/:id/:name route in app/controllers/files.js calls requireLogin and findById, then serves or redirects to the file without checking file.room or Room.canJoin. Exploitation requires an ordinary account, files.enable set to true, and a known or adjacent MongoDB ObjectId; it exposes attachment contents from private or password-protected rooms.
The record
- CVE
- CVE-2026-66750
- Published
- Jul 28, 2026
- Updated
- Jul 28, 2026
- Vendor
- Security Compass
- Product
- Let's Chat
- Classifications
- CWE-862, T1213.005
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 28, 2026CVE publishedPublication date reported by the CVE source.
- Jul 28, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0.3.0 <=0.4.8
- Affected versionversion=55e8833974c83559ed2cbc12bc15febeb2466254 <=617207ff3c0c0bf8e3c7a915bd9ec03f1dd8390c
What conditions does exploitation require?
What is affected?
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.
Weakness, pattern, technique
Public exploit references
- CVE-2026-66750 unauthorized file-download reproductionproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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