Vulnerability · NVD published 2026-10-16
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.
Signals
- Exploited in the wild
- Not on KEVNot in CISA's catalogue as of the last daily pull. Absence is not proof of safety.
- EPSS · 30-day forecast
- not stated by sourcesFIRST has not scored this id yet.
- CVSS · NVD
- not stated by sourcesNo score published by NVD.
- Internet exposure
- not stated by sourcesNo exposure census on this CVE's dispatches.
Exploits
not checkedNot checked yet. Our exploit watch has not looked at this CVE, so this says nothing either way.
On the wire
1 dispatchWatch this one?
KEV additions reach Telegram and the KEV-only RSS as they land.
Check your stack
Paste what you run: the CVEs exploited in the wild against it, and who is cited as exploiting them, with the report.
Stack checkNo key. No signup.