{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-123271","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-11-05T18:19:12.338Z","datePublished":"2026-11-05T18:45:35.481Z","dateUpdated":"2026-11-05T18:45:35.481Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-11-05T18:45:35.481Z"},"datePublic":"2026-10-11T00:00:00.000Z","title":"ChatCLI before v1.215.2 Origin Validation Error via Unvalidated MCP OAuth Resource Indicator","descriptions":[{"lang":"en","value":"ChatCLI before v1.215.2 contains an improper validation vulnerability in the MCP OAuth login flow that uses server-supplied Protected Resource Metadata as the resource indicator without checking it matches the configured server URL. A malicious MCP server can declare another resource on the same authorization server, obtain the user's bearer token for it, and replay that token against the other resource."}],"problemTypes":[{"descriptions":[{"lang":"en","description":"Origin Validation Error","cweId":"CWE-346","type":"CWE"}]}],"affected":[{"vendor":"diillson","product":"ChatCLI","defaultStatus":"unaffected","versions":[{"version":"v1.159.0","lessThan":"v1.215.2","status":"affected","versionType":"semver"}],"packageURL":"pkg:golang/github.com/diillson/chatcli","repo":"https://github.com/diillson/chatcli"}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"ACTIVE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"HIGH","subIntegrityImpact":"HIGH","subAvailabilityImpact":"NONE","baseScore":5.1,"baseSeverity":"MEDIUM"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"CHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"NONE","baseScore":8,"baseSeverity":"HIGH"}}],"references":[{"url":"https://github.com/diillson/chatcli/security/advisories/GHSA-95vg-3r9c-2v5q","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-95vg-3r9c-2v5q)"},{"url":"https://github.com/diillson/chatcli/commit/951fe24b8e090eae86bf8edb13a788916b1e6c91","tags":["patch"]},{"url":"https://github.com/diillson/chatcli/releases/tag/v1.215.2","tags":["release-notes"],"name":"ChatCLI v1.215.2 Release Notes"},{"url":"https://github.com/diillson/chatcli/blob/359eb27debc4de78289a9662551a51ab4528e16c/cli/mcp/oauth.go#L477-L493","tags":["technical-description"]},{"name":"VulnCheck Advisory: ChatCLI before v1.215.2 Origin Validation Error via Unvalidated MCP OAuth Resource Indicator","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/chatcli-before-1.215.2-origin-validation-error-via-unvalidated-mcp-oauth-resource-indicator"}],"credits":[{"lang":"en","value":"Theodoros Lampropoulos","type":"finder"},{"lang":"en","value":"diillson","type":"remediation developer"}],"x_generator":{"engine":"vulncheck-endgame"}}}}