CVEs / CVE-2026-96620
CVE-2026-96620
Claude Agent SDK is a Python SDK for Claude Code. Prior to 0.2.121, the resume option is passed to the Claude CLI as a separate token without validation, so a dash-leading value is parsed as an independent CLI flag. An attacker can inject the --mcp-config flag to define a stdio MCP server, causing arbitrary command execution at CLI startup outside the SDK permission controls. The issue is exploitable when an application passes untrusted input as the session ID to resume. This issue is fixed in version 0.2.121.
Affected products · 1
| Product | Versions affected | Fixed in |
|---|---|---|
| Anthropic: Claude Code | not stated by CPE | — |
Versions as NVD's CPE configuration states them; "—" means the record gives no fixed version, not that none exists. Check the vendor's advisory in the references.
In this registry
- Claude Code — agent dossier
References · 4
- github.com/anthropics/claude-agent-sdk-python/commit/347a1cb88d7652199399db1b7f914e0a459a6
- github.com/anthropics/claude-agent-sdk-python/pull/1123
- github.com/anthropics/claude-agent-sdk-python/releases/tag/v0.2.121
- github.com/anthropics/claude-agent-sdk-python/security/advisories/GHSA-h4mw-j7qp-8mwm
The official record's references, as NVD lists them, minus any tagged Exploit. Nothing here is an exploit or a proof of concept.
Description, scores, versions and references are the official CVE record's own, retrieved 2026-10-25 from NVD. Category, attack surface and cross-links are this registry's classification and can be wrong — use the button above. Not a severity assessment for your deployment.