CVE-2026-91988Network attack vectorHinoki check available

Code execution via cleartext MCP catalog tampering

Published Sep 15, 2026 · Updated Sep 15, 2026

Command injection in dep0we atomic-agents-stack 1.0.0 and earlier allows man-in-the-middle attackers to execute code via HTTP MCP catalogs. The make_http_mcp_server_registry_backend_from_url factory accepts cleartext HTTP, and MCPClientPool spawns unrestricted catalog command and argument values as local subprocesses. Exploitation requires a non-loopback HTTP catalog connection that a network man-in-the-middle can alter; no operator allowlist applies by default.

CVSS severity8.7
High
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Command injection in dep0we atomic-agents-stack 1.0.0 and earlier allows man-in-the-middle attackers to execute code via HTTP MCP catalogs. The make_http_mcp_server_registry_backend_from_url factory accepts cleartext HTTP, and MCPClientPool spawns unrestricted catalog command and argument values as local subprocesses. Exploitation requires a non-loopback HTTP catalog connection that a network man-in-the-middle can alter; no operator allowlist applies by default.

The record

CVE
CVE-2026-91988
Published
Sep 15, 2026
Updated
Sep 15, 2026
Vendor
dep0we
Product
atomic-agents-stack
Classifications
CWE-494, CWE-319, T1059
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <1.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

dep0we · atomic-agents-stackversion=0 <1.1.0

Published CVSS scores

8.7GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-494Download of Code Without Integrity Check
CWE-319Cleartext Transmission of Sensitive Information
T1059Command and Scripting Interpreter

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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