CVE-2026-73222
Unauthenticated OS command injection in Claude Code Studio server (port 3444)
Is CVE-2026-73222 being exploited?
Not confirmed. CVE-2026-73222 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.25% probability of exploitation in the next 30 days.
How severe is CVE-2026-73222?
CVE-2026-73222 is rated High with a CVSS score of 8.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-73222?
Yes. A fix has been recorded for CVE-2026-73222. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-73222 affect?
CVE-2026-73222 affects Claude Code Templates CLI (<1.29.4), Claude Code Studio server (--studio, port 3444). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-73222?
Update to 1.29.4, block/limit access to port 3444, avoid running Studio on untrusted networks.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote arbitrary OS command execution as the developer via unauthenticated POST endpoints, risking code, credentials, and local data theft.
Immediate action required
- affected< 1.29.4
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.