{"api_version":"1","generated_at":"2026-09-14T18:21:38+00:00","cve":"CVE-2026-55235","urls":{"html":"https://cve.report/CVE-2026-55235","api":"https://cve.report/api/cve/CVE-2026-55235.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-55235","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-55235"},"summary":{"title":"langgraph-api: Relative webhook targets in LangGraph Server can reach in-process routes without authentication","description":"langgraph-api implements the LangGraph API for rapid development and testing. Prior to 0.10.0, langgraph-api permits a run or cron to specify a relative webhook target that is delivered through an in-process loopback transport, and the authentication middleware treats that transport as internal without applying the authentication context used for external requests. In deployments that rely on per-user authorization to separate threads and runs, an authenticated user can direct a webhook to the server's own thread and run routes, allowing creation of a run on or modification of another user's thread and limited incorporation of the targeted thread's metadata into the created run record. The affected path requires webhook targets and per-user authorization boundaries; deployments that deliberately re-enable loopback delivery should restrict it to controlled same-process routes because those webhooks remain unauthenticated. This issue is fixed in version 0.10.0.","state":"PUBLISHED","assigner":"GitHub_M","published_at":"2026-09-14 16:17:12","updated_at":"2026-09-14 16:17:12"},"problem_types":["CWE-287","CWE-287 CWE-287: Improper Authentication"],"metrics":[{"version":"3.1","source":"security-advisories@github.com","type":"Secondary","score":"5.9","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L","baseScore":5.9,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"LOW"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"5.9","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L","data":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":5.9,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L","version":"3.1"}}],"references":[{"url":"https://github.com/langchain-ai/docs/blob/7b70fbacab21f84d9c6f9848f86cdeb471adbb50/src/langsmith/agent-server-changelog.mdx","name":"https://github.com/langchain-ai/docs/blob/7b70fbacab21f84d9c6f9848f86cdeb471adbb50/src/langsmith/agent-server-changelog.mdx","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/langchain-ai/helm/security/advisories/GHSA-2c9q-c2q9-qgqv","name":"https://github.com/langchain-ai/helm/security/advisories/GHSA-2c9q-c2q9-qgqv","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-55235","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55235","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"langchain-ai","product":"langgraph-api","version":"affected < 0.10.0","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"product":"langgraph-api","vendor":"langchain-ai","versions":[{"status":"affected","version":"< 0.10.0"}]}],"descriptions":[{"lang":"en","value":"langgraph-api implements the LangGraph API for rapid development and testing. Prior to 0.10.0, langgraph-api permits a run or cron to specify a relative webhook target that is delivered through an in-process loopback transport, and the authentication middleware treats that transport as internal without applying the authentication context used for external requests. In deployments that rely on per-user authorization to separate threads and runs, an authenticated user can direct a webhook to the server's own thread and run routes, allowing creation of a run on or modification of another user's thread and limited incorporation of the targeted thread's metadata into the created run record. The affected path requires webhook targets and per-user authorization boundaries; deployments that deliberately re-enable loopback delivery should restrict it to controlled same-process routes because those webhooks remain unauthenticated. This issue is fixed in version 0.10.0."}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":5.9,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-287","description":"CWE-287: Improper Authentication","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-09-14T15:53:19.013Z","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M"},"references":[{"name":"https://github.com/langchain-ai/helm/security/advisories/GHSA-2c9q-c2q9-qgqv","tags":["x_refsource_CONFIRM"],"url":"https://github.com/langchain-ai/helm/security/advisories/GHSA-2c9q-c2q9-qgqv"},{"name":"https://github.com/langchain-ai/docs/blob/7b70fbacab21f84d9c6f9848f86cdeb471adbb50/src/langsmith/agent-server-changelog.mdx","tags":["x_refsource_MISC"],"url":"https://github.com/langchain-ai/docs/blob/7b70fbacab21f84d9c6f9848f86cdeb471adbb50/src/langsmith/agent-server-changelog.mdx"}],"source":{"advisory":"GHSA-2c9q-c2q9-qgqv","discovery":"UNKNOWN"},"title":"langgraph-api: Relative webhook targets in LangGraph Server can reach in-process routes without authentication"}},"cveMetadata":{"assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","assignerShortName":"GitHub_M","cveId":"CVE-2026-55235","datePublished":"2026-09-14T15:53:19.013Z","dateReserved":"2026-06-16T16:44:00.623Z","dateUpdated":"2026-09-14T15:53:19.013Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-14 16:17:12","lastModifiedDate":"2026-09-14 16:17:12","problem_types":["CWE-287","CWE-287 CWE-287: Improper Authentication"],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L","baseScore":5.9,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"LOW"},"exploitabilityScore":1.6,"impactScore":4.2}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"55235","Ordinal":"1","Title":"langgraph-api: Relative webhook targets in LangGraph Server can ","CVE":"CVE-2026-55235","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"55235","Ordinal":"1","NoteData":"langgraph-api implements the LangGraph API for rapid development and testing. Prior to 0.10.0, langgraph-api permits a run or cron to specify a relative webhook target that is delivered through an in-process loopback transport, and the authentication middleware treats that transport as internal without applying the authentication context used for external requests. In deployments that rely on per-user authorization to separate threads and runs, an authenticated user can direct a webhook to the server's own thread and run routes, allowing creation of a run on or modification of another user's thread and limited incorporation of the targeted thread's metadata into the created run record. The affected path requires webhook targets and per-user authorization boundaries; deployments that deliberately re-enable loopback delivery should restrict it to controlled same-process routes because those webhooks remain unauthenticated. This issue is fixed in version 0.10.0.","Type":"Description","Title":"langgraph-api: Relative webhook targets in LangGraph Server can "}]}}}