CVE-2026-81096Network attack vector

Unauthenticated code execution via Python sandbox escape

Published Aug 27, 2026 · Updated Aug 27, 2026

Sandbox escape in Harvard University ToolUniverse 1.2.6 and earlier allows remote attackers to execute code through python_code_executor. The executor checks source against a denylist but leaves string-based and permitted-module attribute pivots that expose class hierarchies and process-launch modules. A reachable HTTP or MCP server requires no authentication, so exploitation runs commands with the server process privileges.

CVSS severityUnavailable
Unscored
EPSS probability0.57%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Sandbox escape in Harvard University ToolUniverse 1.2.6 and earlier allows remote attackers to execute code through python_code_executor. The executor checks source against a denylist but leaves string-based and permitted-module attribute pivots that expose class hierarchies and process-launch modules. A reachable HTTP or MCP server requires no authentication, so exploitation runs commands with the server process privileges.

The record

CVE
CVE-2026-81096
Published
Aug 27, 2026
Updated
Aug 27, 2026
Vendor
Harvard University
Product
ToolUniverse
Classifications
T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 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 <=1.2.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Harvard University · ToolUniverseversion=0 <=1.2.6

Published CVSS scores

No CVSS assessment is available in this record.

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.

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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

T1190Exploit Public-Facing Application

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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