CVE-2026-91987 atomic-agents-stack before 1.1.0 Cost Guardrail Bypass via Unknown Model
Attackers can bypass cost guardrails by using unknown model identifiers, allowing them to exceed budget limits in parallel batch operations.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-91987?
CVE-2026-91987 is a high-severity vulnerability in dep0we atomic-agents-stack, published on 15 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-770
Which versions are affected by CVE-2026-91987?
2 open source packages ship an affected version, including atomic-agents-stack.
| Package | Affected | Fixed in |
|---|---|---|
atomic-agents-stack PyPI | All versions | 1.1.0 |
atomic-agents-stack PyPI | All versions | 1.1.0 |
How do I fix CVE-2026-91987?
Upgrade atomic-agents-stack to 1.1.0 or later.
Is CVE-2026-91987 being exploited?
There is no known exploitation of CVE-2026-91987 in the wild and no public exploit code.
Sources
Also known as GHSA-gpqc-jrqh-x9xp, GHSA-j659-8xh6-5pq5.