CVE-2026-86115: Unintended Proxy or Intermediary ('Confused Deputy') in simstudioai sim
Description
Sim before 0.8.14 classifies tool requests as internal based on URL prefix matching without scheme normalization, skipping SSRF validation and minting internal authentication tokens. Authenticated workflow authors can bypass external URL validation by supplying paths starting with /api/ in HTTP blocks to reach internal-only endpoints like POST /api/function/execute.
CVSS v4.0
Score 5.3medium
Affected software
simstudioai
sim
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in simstudioai sim versions prior to 0.8.14 involves improper classification of tool requests as internal due to URL prefix matching without scheme normalization. This leads to skipping server-side request forgery (SSRF) validation and unauthorized minting of internal authentication tokens. Authenticated users with workflow author privileges can exploit this by supplying paths beginning with /api/ in HTTP blocks, thereby reaching internal endpoints that should be restricted, including POST /api/function/execute.
Potential Impact
An authenticated workflow author can bypass external URL validation controls and access internal-only endpoints. This may allow unauthorized internal actions via endpoints like POST /api/function/execute, potentially leading to unintended proxying or privilege escalation within the application context. The CVSS 4.0 base score is 5.3, indicating a medium severity impact with network attack vector, low complexity, and no user interaction required.
Mitigation Recommendations
A fix is available in simstudioai sim version 0.8.14 and later. Users should upgrade to version 0.8.14 or newer to remediate this vulnerability. No additional mitigation guidance is provided or required beyond applying the official fix.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-09-05T01:59:20.600Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6a9bed73acd9273b49b1c66c
Added to database: 09/05/2026, 10:22:43 UTC
Last enriched: 09/25/2026, 02:47:15 UTC
Last updated: 10/18/2026, 18:48:24 UTC
Views: 67
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