ModelScope MS-Agent Shell Tool Unsanitized Argv RCE (CVE-2026-2256) - ATR-2026-00530 (50db0326-38ad-513b-be44-396316a46ba3)
Detects the agent-tool RCE class exploited by CVE-2026-2256 in the ModelScope MS-Agent framework (CVSS 9.8). Original disclosure CERT/CC VU#431821 dated 2026-03-02; SecurityWeek republication brought renewed attention 2026-05-19. The MS-Agent Shell tool passes user-influenced input directly to a shell execution context without sanitization, providing a prompt-to-RCE primitive. MS-Agent has strong APAC adoption. The detection target is shell-tool invocation shapes whose argument comes verbatim from user input or LLM output, with the dangerous characteristic being absence of argv splitting / shlex.quote / explicit allowlist. Generalizes beyond MS-Agent to any agent shell-tool wrapper that does the same.