CVE-2026-3432
Published: 02 March 2026
Summary
CVE-2026-3432 is a critical-severity Missing Authorization (CWE-862) vulnerability in Sim Sim. Its CVSS base score is 9.3 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 21.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 AC-3 (Access Enforcement) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2026-3432 is a critical authorization bypass vulnerability (CWE-862) in SimStudio versions below 0.5.74, specifically within the `/api/auth/oauth/token` endpoint. This flaw enables a code path that skips all authorization checks when the `credentialAccountUserId` and `providerId` parameters are supplied, allowing unauthorized retrieval of sensitive OAuth data. The issue carries a CVSS v3.1 base score of 9.1 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N), highlighting its high severity due to network accessibility, low complexity, and lack of prerequisites.
Unauthenticated attackers can exploit this vulnerability remotely by providing any target user's ID along with a provider name via the affected endpoint. Successful exploitation grants the attacker the victim's OAuth access tokens, enabling credential theft and subsequent unauthorized access to linked third-party services.
The Tenable research advisory (TRA-2026-13) at https://www.tenable.com/security/research/tra-2026-13 details mitigation strategies, including upgrading to SimStudio version 0.5.74 or later to address the bypass.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-9173
Vulnerability details
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…
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ID and a provider name, effectively stealing credentials to third-party services.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The vulnerability is an authorization bypass in a public-facing API endpoint (T1190: Exploit Public-Facing Application), directly enabling theft of OAuth access tokens for any user (T1528: Steal Application Access Token).
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Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
AC-3 mandates enforcement of approved authorizations for access to sensitive resources like OAuth tokens, directly countering the bypass of authorization checks in the /api/auth/oauth/token endpoint.
SI-2 requires timely identification, reporting, and correction of flaws such as the authorization bypass, enabling patching to SimStudio 0.5.74 or later as recommended.
SI-10 requires validation of information inputs like credentialAccountUserId and providerId to prevent unauthorized parameter-driven bypasses of authorization logic.