{"schemaVersion":3,"id":"CVE-2026-34237","aliases":["CGA-3pqm-cvjx-3xqf","CGA-542f-52h9-p3g3","CGA-697p-27x4-m8m9","CGA-7c2g-hv4p-x66c","CGA-7cvq-xpjv-p3gj","CGA-9qf7-9rm6-x6v4","CGA-c64p-94rf-q9fp","CGA-fp4w-9q9h-g9mw","GHSA-hv2w-8mjj-jw22"],"status":"published","duplicateOf":null,"title":null,"description":"MCP Java SDK is the official Java SDK for Model Context Protocol servers and clients. Prior to versions 0.83.0, 1.0.1, and 1.1.1, there is a hardcoded wildcard CORS vulnerability. This issue has been patched in versions 0.83.0, 1.0.1, and 1.1.1.","dates":{"published":"2026-03-31T15:40:01.070Z","modified":"2026-06-09T18:39:37.473Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":6.1,"severity":"medium","version":"3.1","versionLabel":"v3.1","source":"CVE.org","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":6.1,"severity":"medium","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Chainguard","score":6.1,"severity":"medium","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","exploitability":7.2,"impact":4.5,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Maven","score":6.1,"severity":"medium","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","exploitability":7.2,"impact":4.5,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":6.1,"severity":"medium","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.0031,"percentile":0.22404,"severity":"low","asOf":"2026-10-20T00:00:00.000Z","change":{"pp":0.08799999999999997,"baselineDate":"2026-09-20T00:00:00.000Z","baselineScore":0.00222},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.00222,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.00222,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.00222,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.00222,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.00222,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.00222,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00222,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00222,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00222,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00222,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.0031,"percentile":0.22404}],"last30":[{"date":"2026-09-20T00:00:00.000Z","score":0.00222,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00222,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00222,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00222,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.0031,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.0031,"percentile":0.22404}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[{"id":"CWE-942","name":"Permissive Cross-domain Security Policy with Untrusted Domains","description":"The product uses a web-client protection\n         mechanism such as a Content Security Policy (CSP) or\n         cross-domain policy file, but the policy includes untrusted\n         domains with which the web client is allowed to\n         communicate.","type":"weakness","status":"Incomplete","abstraction":"Variant","likelihoodOfExploit":null,"url":"https://cwe.mitre.org/data/definitions/942.html"}],"affected":[{"vendor":"chainguard","product":"camunda-8.9","name":"camunda-8.9","label":"camunda-8.9","ecosystem":"Chainguard","cpePart":null,"purl":"pkg:apk/chainguard/camunda-8.9","purlType":"apk","versions":[{"text":"< 8.9.1-r0","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 8.9.1-r0","eol":null,"hubHref":null},{"vendor":"chainguard","product":"camunda-zeebe-8.9","name":"camunda-zeebe-8.9","label":"camunda-zeebe-8.9","ecosystem":"Chainguard","cpePart":null,"purl":"pkg:apk/chainguard/camunda-zeebe-8.9","purlType":"apk","versions":[{"text":"< 8.9.1-r0","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 8.9.1-r0","eol":null,"hubHref":null},{"vendor":"chainguard","product":"nacos","name":"nacos","label":"nacos","ecosystem":"Chainguard","cpePart":null,"purl":"pkg:apk/chainguard/nacos","purlType":"apk","versions":[{"text":"< 3.2.0-r6","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 3.2.0-r6","eol":null,"hubHref":null},{"vendor":"chainguard","product":"nacos-docker","name":"nacos-docker","label":"nacos-docker","ecosystem":"Chainguard","cpePart":null,"purl":"pkg:apk/chainguard/nacos-docker","purlType":"apk","versions":[{"text":"< 3.2.0-r2","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 3.2.0-r2","eol":null,"hubHref":null},{"vendor":"lfprojects","product":"mcp_java_sdk","name":"mcp java sdk","label":"mcp_java_sdk","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"< 1.0.1","noFixRecorded":false,"fixedIn":null},{"text":"1.1.0","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 1.0.1 | 1.1.0","eol":null,"hubHref":"/vendor/lfprojects/mcp_java_sdk"},{"vendor":"io.modelcontextprotocol.sdk","product":"mcp-core","name":"io.modelcontextprotocol.sdk:mcp-core","label":"mcp-core","ecosystem":"Maven","cpePart":null,"purl":"pkg:maven/io.modelcontextprotocol.sdk/mcp-core","purlType":"maven","versions":[{"text":"≥ 1.0.0, < 1.0.1","noFixRecorded":false,"fixedIn":null},{"text":"≥ 1.1.0, < 1.1.1","noFixRecorded":false,"fixedIn":null},{"text":"< 0.18.3","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 1.0.0, < 1.0.1 | ≥ 1.1.0, < 1.1.1 | < 0.18.3","eol":null,"hubHref":null},{"vendor":"modelcontextprotocol","product":"java-sdk","name":"java-sdk","label":"java-sdk","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 1.0.0, < 1.0.1","noFixRecorded":false,"fixedIn":null},{"text":"≥ 1.1.0, < 1.1.1","noFixRecorded":false,"fixedIn":null},{"text":"< 0.18.3","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 1.0.0, < 1.0.1 | ≥ 1.1.0, < 1.1.1 | < 0.18.3","eol":null,"hubHref":"/vendor/modelcontextprotocol/java-sdk"}],"affectedCount":7,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://github.com/modelcontextprotocol/java-sdk/security/advisories/GHSA-hv2w-8mjj-jw22","label":"github.com/modelcontextprotocol/java-sdk/security/advisories/GHSA-hv2w-8mjj-jw22","hostname":"github.com","tags":["X Refsource CONFIRM","Advisory","WEB","Mitigation","Vendor Advisory"]},{"url":"https://github.com/modelcontextprotocol/java-sdk/blob/main/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/HttpServletSseServerTransportProvider.java#L289","label":"github.com/modelcontextprotocol/…","hostname":"github.com","tags":["X Refsource MISC","WEB","Patch"]},{"url":"https://github.com/modelcontextprotocol/java-sdk/blob/main/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/HttpServletStreamableServerTransportProvider.java#L525","label":"github.com/modelcontextprotocol/…","hostname":"github.com","tags":["X Refsource MISC","WEB","Patch"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34237.json","label":"github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34237.json","hostname":"github.com","tags":["Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34237","label":"nvd.nist.gov/vuln/detail/CVE-2026-34237","hostname":"nvd.nist.gov","tags":["Advisory"]},{"url":"https://cheatsheetseries.owasp.org/cheatsheets/HTTP_Headers_Cheat_Sheet.html#access-control-allow-origin","label":"cheatsheetseries.owasp.org/cheatsheets/HTTP_Headers_Cheat_Sheet.html","hostname":"cheatsheetseries.owasp.org","tags":["WEB"]},{"url":"https://github.com/modelcontextprotocol/java-sdk","label":"github.com/modelcontextprotocol/java-sdk","hostname":"github.com","tags":["PACKAGE"]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":["CGA-RPQR-576X-6RXX"]},"timeline":[{"kind":"published","date":"2026-03-31T15:40:01.070Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-06-09T18:39:37.473Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":24,"level":"low","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-21T01:14:42.036Z","stale":false,"partial":false}}