Auth bypass in Sim

CVE-2026-3432

On SimStudio version below to 0.5.74, the `/api/auth/oauth/token` endpoint contains a code path that bypasses all authorization checks when provided with `credentialAccountUserId` and `providerId` parameters. An unauthenticated attacker can retrieve OAuth access tokens for any user by supplying their user ID and a provider name, effectively stealing credentials to third-party services.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.004 (36.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 36.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-3432: held from 0.003 to 0.004.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-3432?
CVE-2026-3432 is a critical-severity vulnerability in Sim, classified under Missing Authorization. CVSS score: 9.1/10. Published 2026-03-02.
How severe is CVE-2026-3432?
Critical severity. CVSS v3 base score is 9.1 out of 10.