CVE-2026-91988: atomic-agents-stack before 1.1.0 Remote Code Execution via HTTP MCP

Severity: high (CVSS 8.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-15 · updated 2026-09-24
Weakness: CWE-319

Description

atomic-agents-stack before 1.1.0 accepts cleartext HTTP schemes in the HTTP MCP server-registry backend factory, allowing network man-in-the-middle attackers to rewrite catalog responses. Attackers can inject arbitrary command and argument values that are spawned as local subprocesses by MCPClientPool to achieve code execution on the agent host.

Affected products

dep0we atomic-agents-stack: before 1.1.0 — fixed in 1.1.0

How to fix

Upgrade to a fixed version: dep0we atomic-agents-stack 1.1.0. Check the vendor advisory for mitigations.

References

https://github.com/dep0we/atomic-agents-stack/security/advisories/GHSA-xhcr-cqfr-m3hv
https://www.vulncheck.com/advisories/atomic-agents-stack-before-1.1.0-remote-code-execution-via-http-mcp

Get alerted when CVE-2026-91988 or the next vulnerability affects your stack