SimpleChat: Authenticated users can access other users' profile metadata through user IDOR endpoints

published 2026-07-16 3 mo ago modified 2026-10-24 15 d ago also EUVD-2026-44941

cvss: 4.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.9%; EPSS 0.9% chance of exploitation in 30 days, percentile 60%
public exploits: 0; none known

SimpleChat is a secure AI conversation application with personal and group workspaces for document-grounded interactions. Prior to 0.241.203, the authenticated GET /api/user/info/<user_id> and GET /api/user/profile-image/<user_id> endpoints in application/single_app/route_backend_users.py accepted a caller-supplied user_id and read the matching Cosmos DB user-settings document without object-level authorization, allowing a low-privilege authenticated user to retrieve another user's email address, display name, and profile image. This issue is fixed in version 0.241.203.

Patch / fix

links 1

github.com/microsoft/simplechat/releases/tag/v0.250.001 release

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 3 mo ago (2026-07-16)

Exploit prediction

0.91% chance of exploitation in the next 30 days, higher than 60% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Affected products

microsoft simplechat

Classification

Weakness

CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
CWE-639 Authorization Bypass Through User-Controlled Key
CWE-862 Missing Authorization

References

Sources

CVE List CVE-2026-57205
NVD CVE-2026-57205

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary