---
id: CVE-2026-91988
title: >-
  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
summary: >-
  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 argume…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-319
vendor: dep0we
product: atomic-agents-stack
affected:
  - atomic-agents-stack < 1.1.0
patched:
  - atomic-agents-stack 1.1.0
published: '2026-09-15'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T20:43:32.537'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91988'
references:
  - url: >-
      https://github.com/dep0we/atomic-agents-stack/security/advisories/GHSA-xhcr-cqfr-m3hv
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/atomic-agents-stack-before-1.1.0-remote-code-execution-via-http-mcp
    label: disclosure@vulncheck.com
  - url: 'https://github.com/dep0we/atomic-agents-stack'
  - url: 'https://github.com/dep0we/atomic-agents-stack/releases#release-v1.1.0'
tags:
  - nvd
  - cve.org
  - osv
  - pip
epss: 0.00318
epssPercentile: 0.22162
aliases:
  - GHSA-xhcr-cqfr-m3hv
ecosystem: pip
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-15T15:48:34.188589Z'
ingestedAt: '2026-09-15T15:39:12.908Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-91988)

Affected packages:

- `atomic-agents-stack < 1.1.0`

Patched in:

- `atomic-agents-stack 1.1.0`

Source: https://osv.dev/vulnerability/GHSA-xhcr-cqfr-m3hv