# CVE-2026-91987

## Summary

- **CVE ID:** CVE-2026-91987
- **Severity:** HIGH
- **CVSS Score:** 7.1 (CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N)
- **CWE:** CWE-770
- **Published:** Sep 15, 2026
- **Last Modified:** Sep 17, 2026

## Description

atomic-agents-stack before 1.1.0 contains a cost-guardrail bypass in the _estimate_batch_cost function that returns zero cost for unknown models not in the pricing table. Attackers can configure deployments with unknown model identifiers to bypass daily cost caps and exceed budget limits in parallel batch operations.

## Affected Products

- dep0we — atomic-agents-stack (0)
- dep0we — atomic-agents-stack (1.1.0)

## References

- [CNA](https://github.com/dep0we/atomic-agents-stack/security/advisories/GHSA-j659-8xh6-5pq5)
- [CNA](https://www.vulncheck.com/advisories/atomic-agents-stack-before-1.1.0-cost-guardrail-bypass-via-unknown-model)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.37%
- **EPSS Percentile:** 30.7

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._