CVE-2026-16481
SSRF leaks OAuth/service-account tokens from googleapis/mcp-toolbox, exposing GCP and PHI
Is CVE-2026-16481 being exploited?
Not confirmed. CVE-2026-16481 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 0.22% probability of exploitation in the next 30 days.
How severe is CVE-2026-16481?
CVE-2026-16481 is rated High with a CVSS score of 8.4. 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-2026-16481?
Not known from our data. No patch reference has been recorded for CVE-2026-16481, which is not the same as no patch existing — a fix may have shipped without a tagged reference, or after this record was written. The vendor advisory is the only authority on whether a fix exists, and mitigations may be available regardless.
What does CVE-2026-16481 affect?
CVE-2026-16481 affects googleapis/mcp-toolbox: cloud-healthcare-fhir-fetch-page, Google Cloud projects using ADC/service-account credentials, Systems processing FHIR data via the toolbox. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-16481?
Update toolbox if patched, rotate service-account/user tokens, restrict egress/metadata access, validate pageURL inputs
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
SSRF causes authenticated requests to attacker URLs, exfiltrating Authorization: Bearer tokens and enabling unauthorized GCP access and PHI/data theft.
Immediate action required
- affected>= 0.19.1 and <= 1.4.0
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.