Auth bypass in a widely-used Google API library; could enable unauthorized access across services.
CVE-2026-11718
OAuth2 token validation bypass in googleapis MCP toolbox.
Is CVE-2026-11718 being exploited?
Not confirmed. CVE-2026-11718 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 0.18% probability of exploitation in the next 30 days.
How severe is CVE-2026-11718?
CVE-2026-11718 is rated Critical with a CVSS score of 9.3. 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-2026-11718?
Yes. A fix has been recorded for CVE-2026-11718. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-11718 affect?
CVE-2026-11718 affects googleapis/mcp-toolbox. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-11718?
Patch when available; harden issuer checks; monitor OAuth introspection activity.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authentication bypass: accepts tokens from untrusted providers, enabling access to protected resources.
Patch when possible
- affected>= 1.0.0 and <= 1.3.0
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.