Unauthenticated RCE via STDIO transport override
Published Apr 29, 2026 · Updated Apr 29, 2026
Command injection in Arc53 DocsGPT 0.15.0 through 0.15.x allows remote attackers to execute arbitrary commands via MCP test requests. The test_connection flow validates server_url but honors an attacker-supplied transport_type of stdio, then _create_transport passes command and args into FastMCP StdioTransport. No authentication or user interaction is required when the backend API is network-reachable, and successful exploitation grants control of the DocsGPT service host.
Summary
What happened
Command injection in Arc53 DocsGPT 0.15.0 through 0.15.x allows remote attackers to execute arbitrary commands via MCP test requests. The test_connection flow validates server_url but honors an attacker-supplied transport_type of stdio, then _create_transport passes command and args into FastMCP StdioTransport. No authentication or user interaction is required when the backend API is network-reachable, and successful exploitation grants control of the DocsGPT service host.
The record
- CVE
- CVE-2026-26015
- Published
- Apr 29, 2026
- Updated
- Apr 29, 2026
- Vendor
- Arc53
- Product
- DocsGPT
- Classifications
- CWE-77, T1190, T1059
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 29, 2026CVE publishedPublication date reported by the CVE source.
- Apr 29, 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.
- Affected versionversion=>= 0.15.0, < 0.16.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
- GHSA-gcrq-f296-2j74 reproduction scriptfunctional · demonstrated
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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