Vulnerability · Published Sep 15, 2026 · Assigned by VulnCheck

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

High 8.1

In plain English

A high-severity security flaw in atomic-agents-stack from dep0we. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)0.3%top 75.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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 packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	atomic-agents-stack	1.1.0	GHSA-xhcr-cqfr-m3hv

Affected products (as reported)

Vendor	Product	Versions
dep0we	atomic-agents-stack	0 – before 1.1.0

Weakness: CWE-319 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

GitHub Security Advisory (GHSA-xhcr-cqfr-m3hv) vendor-advisory
VulnCheck Advisory: atomic-agents-stack before 1.1.0 Remote Code Execution via HTTP MCP third-party-advisory