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CVE-2026-9739

Vulnerable to DNS rebinding attacks when using SSE (http://b/499408790). During the beta phase, we implemented `allowed-origins` and `allowed-hosts` flags to align with MCP security guidelines. However, the hardcoded `Access-Control-Allow-Origin: *` header in the SSE initialization handler was inadvertently retained. This vulnerability specifically impacts users connecting via Toolbox using SSE under specification v2024-11-05.
Lifecycle PUBLISHED1 preserved revisionFact urn:baitaphish:canonical-cve-fact-revision:v2:c2b3870aa1035ffeff522510f3d67de96c3bee538cfd0711c6fb87a70c8e00e3
Known exploited
Not asserted
Disputed
No
Stale source
No
Conflicts
0

Affected products and versions

1 source assertion
{"defaultStatus":"unaffected","product":"MCP Toolbox for Databases","vendor":"Google","versions":[{"lessThan":"PR 3054 (Fix CORS bypass)","status":"affected","version":"0","versionType":"custom"}]}
  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:2e6f04fb21840ef7897924d4c8cee00c5a4b10e481d7056dc3453fcad1916a81 · sha256:70792f367ee81f33… · /containers/cna/affected/0

Provider-owned CVSS observations

1 source assertion
{"metric":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":9.4,"baseSeverity":"CRITICAL","exploitMaturity":"NOT_DEFINED","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"HIGH","subConfidentialityImpact":"HIGH","subIntegrityImpact":"HIGH","userInteraction":"ACTIVE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImp…
  • cve_program_cvelist_v5cvss
    urn:baitaphish:normalized-source-record:v2:2e6f04fb21840ef7897924d4c8cee00c5a4b10e481d7056dc3453fcad1916a81 · sha256:70792f367ee81f33… · /containers/cna/metrics/0/cvssV4_0

CWE assertions

1 source assertion
{"cweId":"CWE-942","description":"CWE-942: Permissive Cross-domain Policy with Untrusted Domains","lang":"en","type":"CWE"}
  • cve_program_cvelist_v5cwe
    urn:baitaphish:normalized-source-record:v2:2e6f04fb21840ef7897924d4c8cee00c5a4b10e481d7056dc3453fcad1916a81 · sha256:70792f367ee81f33… · /containers/cna/problemTypes/0/descriptions/0

Source references

2 source assertions
{"url":"https://github.com/googleapis/mcp-toolbox/issues/3053"}
  • cve_program_cvelist_v5reference
    urn:baitaphish:normalized-source-record:v2:2e6f04fb21840ef7897924d4c8cee00c5a4b10e481d7056dc3453fcad1916a81 · sha256:70792f367ee81f33… · /containers/cna/references/0
{"url":"https://github.com/googleapis/mcp-toolbox/pull/3054"}
  • cve_program_cvelist_v5reference
    urn:baitaphish:normalized-source-record:v2:2e6f04fb21840ef7897924d4c8cee00c5a4b10e481d7056dc3453fcad1916a81 · sha256:70792f367ee81f33… · /containers/cna/references/1

Attribution and limitations

  • CVE Program CVEList V5: Reproduce the MITRE copyright designation and CVE license in copies. Source →

Provider severity values are preserved separately. Baitaphish does not convert them into a risk rating, infer affected products, or treat EPSS as observed exploitation.

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