Vulnerability · Published Sep 5, 2026 · Assigned by VulnCheck
CVE-2026-86115Sim before 0.8.14 Confused Deputy in Tool URL Routing Mints an Internal Token for a User-Supplied /api/ Path
Medium 5.0
In plain English
A medium-severity security flaw in sim from simstudioai. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 43% of all known vulnerabilities).
Severity (CVSS 3.1)5.0Medium
Exploit odds (30 days)0.5%top 57.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| simstudioai | sim | 0 – before 0.8.14 |
Weakness: CWE-441 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N
References
- Researcher write-up technical-description
- isInternalRoute prefix check and addInternalAuthIfNeeded technical-description
- checkInternalAuth accepts the minted internal JWT technical-description
- refactor(tools): execute internal operations in process (#7179) patch, issue-tracking
- https://github.com/simstudioai/sim product
- VulnCheck Advisory: Sim before 0.8.14 Confused Deputy in Tool URL Routing Mints an Internal Token for a User-Supplied /api/ Path third-party-advisory