CVE-2026-86115

5.3 mediumEPSS 0.5%

Medium (5.3). EPSS 0.5% chance of exploitation in the next 30 days.

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.

Severity

CVSS 4.0

5.3 medium

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N

CVSS 3.1

5.0 medium

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N

EPSS: 0.5% chance of exploitation in the next 30 days; higher than 42% of CVEs (scores of 2026-10-31)
CWE: CWE-441
Published: 2026-09-05
Modified: 2026-09-23
Record from: the NVD, synced 2026-10-19

References

https://github.com/geo-chen/oss/blob/main/sim.md
https://github.com/simstudioai/sim
https://github.com/simstudioai/sim/blob/v0.8.13/apps/sim/lib/auth/hybrid.ts
https://github.com/simstudioai/sim/blob/v0.8.13/apps/sim/tools/index.ts
https://github.com/simstudioai/sim/pull/7179

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