CVE-2026-67531: CWE-94: Improper Control of Generation of Code ('Code Injection') in agentfront frontmcp
CVE-2026-67531 is a critical remote code execution vulnerability in the agentfront frontmcp framework prior to version 1.5.7. It arises from improper control of code generation due to exposure of live host Zod schema instances in sandboxed scripts. This allows an attacker to escape the sandbox and execute arbitrary code with the server user's privileges, potentially exposing sensitive secrets and credentials. The vulnerability is fixed in version 1.5.7.
AI Analysis
Technical Summary
The vulnerability in frontmcp (CVE-2026-67531) involves the sandboxed codecall:execute tool exposing live host Zod schema instances to scripts via getTool(). Because Zod v4 defines a non-configurable, non-writable property (_zod), ECMAScript Proxy invariants cause the security membrane to return the raw host object. This enables scripts to access _zod.constr.constructor, the host Function constructor, allowing arbitrary code execution on the server process. The default public mode authentication option exposes this to unauthenticated callers, and indirect prompt injection can trigger it on authenticated servers. This issue is resolved in frontmcp version 1.5.7.
Potential Impact
Successful exploitation allows remote attackers to execute arbitrary code on the server process with the server user's privileges. This can lead to exposure of sensitive data including OAuth client secrets, JWT_SECRET, session keys, database credentials, and cloud instance metadata. The vulnerability requires no authentication and can be triggered remotely, making it highly severe.
Mitigation Recommendations
Upgrade frontmcp to version 1.5.7 or later, where this vulnerability is fixed. No other official remediation or temporary fix is documented. Until upgrading, restrict access to the vulnerable tool and avoid running untrusted scripts in the sandboxed environment.
CVE-2026-67531: CWE-94: Improper Control of Generation of Code ('Code Injection') in agentfront frontmcp
Description
CVE-2026-67531 is a critical remote code execution vulnerability in the agentfront frontmcp framework prior to version 1.5.7. It arises from improper control of code generation due to exposure of live host Zod schema instances in sandboxed scripts. This allows an attacker to escape the sandbox and execute arbitrary code with the server user's privileges, potentially exposing sensitive secrets and credentials. The vulnerability is fixed in version 1.5.7.
CVSS v4.0
Score 9.3critical
Affected software
pkg:github/agentfront/frontmcpRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in frontmcp (CVE-2026-67531) involves the sandboxed codecall:execute tool exposing live host Zod schema instances to scripts via getTool(). Because Zod v4 defines a non-configurable, non-writable property (_zod), ECMAScript Proxy invariants cause the security membrane to return the raw host object. This enables scripts to access _zod.constr.constructor, the host Function constructor, allowing arbitrary code execution on the server process. The default public mode authentication option exposes this to unauthenticated callers, and indirect prompt injection can trigger it on authenticated servers. This issue is resolved in frontmcp version 1.5.7.
Potential Impact
Successful exploitation allows remote attackers to execute arbitrary code on the server process with the server user's privileges. This can lead to exposure of sensitive data including OAuth client secrets, JWT_SECRET, session keys, database credentials, and cloud instance metadata. The vulnerability requires no authentication and can be triggered remotely, making it highly severe.
Mitigation Recommendations
Upgrade frontmcp to version 1.5.7 or later, where this vulnerability is fixed. No other official remediation or temporary fix is documented. Until upgrading, restrict access to the vulnerable tool and avoid running untrusted scripts in the sandboxed environment.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-07-29T18:47:17.073Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a73c6b4bf8831d5399d0b73
Added to database: 08/05/2026, 23:26:44 UTC
Last enriched: 08/13/2026, 17:15:06 UTC
Last updated: 08/16/2026, 07:18:46 UTC
Views: 76
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