{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-40110", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-04-09T01:41:38.536Z", "datePublished": "2026-05-05T21:29:31.323Z", "dateUpdated": "2026-07-22T12:08:40.428Z" }, "containers": { "cna": { "title": "jupyter-server CORS origin validation bypass via unanchored regex in allow_origin_pat", "problemTypes": [ { "descriptions": [ { "cweId": "CWE-777", "lang": "en", "description": "CWE-777: Regular Expression without Anchors", "type": "CWE" } ] } ], "metrics": [ { "cvssV4_0": { "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "LOW", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "subAvailabilityImpact": "LOW", "baseScore": 7.6, "baseSeverity": "HIGH", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:L/SC:L/SI:L/SA:L", "version": "4.0" } } ], "references": [ { "name": "https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-24qx-w28j-9m6p", "tags": [ "x_refsource_CONFIRM" ], "url": "https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-24qx-w28j-9m6p" }, { "name": "https://github.com/jupyter-server/jupyter_server/pull/603", "tags": [ "x_refsource_MISC" ], "url": "https://github.com/jupyter-server/jupyter_server/pull/603" }, { "name": "https://github.com/jupyter-server/jupyter_server/commit/057869a327c46730afede3eab0ca2d2e3e74acea", "tags": [ "x_refsource_MISC" ], "url": "https://github.com/jupyter-server/jupyter_server/commit/057869a327c46730afede3eab0ca2d2e3e74acea" }, { "name": "https://github.com/jupyter-server/jupyter_server/commit/49b34392feaa97735b3b777e3baf8f22f2a14ed8", "tags": [ "x_refsource_MISC" ], "url": "https://github.com/jupyter-server/jupyter_server/commit/49b34392feaa97735b3b777e3baf8f22f2a14ed8" } ], "affected": [ { "vendor": "jupyter-server", "product": "jupyter_server", "versions": [ { "version": "<= 2.17.0", "status": "affected" } ] } ], "providerMetadata": { "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-05-05T21:29:31.323Z" }, "descriptions": [ { "lang": "en", "value": "Jupyter Server is the backend for Jupyter web applications. In versions 2.17.0 and earlier, the Origin header validation uses Python's re.match() to check incoming origins against the allow_origin_pat configuration value. Because re.match() only anchors at the start of the string and does not require a full match, a pattern intended to match only a trusted domain (e.g., trusted.example.com) will also match any origin that begins with that domain followed by additional characters (e.g., trusted.example.com.evil.com). An attacker who controls such a domain can bypass the CORS origin restriction and make cross-origin requests to the Jupyter Server API from an untrusted site. This issue has been fixed in version 2.18.0." } ], "source": { "advisory": "GHSA-24qx-w28j-9m6p", "discovery": "UNKNOWN" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-05-07T03:55:47.112003Z", "id": "CVE-2026-40110", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-05-07T12:47:52.707Z" } }, { "affected": [ { "collectionURL": "https://catalog.redhat.com/software/containers/", "cpes": [ "cpe:/a:redhat:migration_toolkit_applications:8.2::el9" ], "defaultStatus": "affected", "packageName": "mta/mta-solution-server-rhel9", "product": "Red Hat Migration Toolkit for Applications 8.2", "vendor": "Red Hat", "versions": [ { "lessThan": "*", "status": "unaffected", "version": "1784109883", "versionType": "rpm" } ] }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:openshift_ai" ], "defaultStatus": "affected", "packageName": "rhoai/odh-workbench-jupyter-datascience-cpu-py312-rhel9", "product": "Red Hat OpenShift AI (RHOAI)", "vendor": "Red Hat" }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:openshift_ai" ], "defaultStatus": "affected", "packageName": "rhoai/odh-workbench-jupyter-minimal-cpu-py312-rhel9", "product": "Red Hat OpenShift AI (RHOAI)", "vendor": "Red Hat" }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:openshift_ai" ], "defaultStatus": "affected", "packageName": "rhoai/odh-workbench-jupyter-minimal-cuda-py312-rhel9", "product": "Red Hat OpenShift AI (RHOAI)", "vendor": "Red Hat" }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:openshift_ai" ], "defaultStatus": "affected", "packageName": "rhoai/odh-workbench-jupyter-minimal-rocm-py312-rhel9", "product": "Red Hat OpenShift AI (RHOAI)", "vendor": "Red Hat" }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:openshift_ai" ], "defaultStatus": "affected", "packageName": "rhoai/odh-workbench-jupyter-pytorch-cuda-py312-rhel9", "product": "Red Hat OpenShift AI (RHOAI)", "vendor": "Red Hat" }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:openshift_ai" ], "defaultStatus": "affected", "packageName": "rhoai/odh-workbench-jupyter-pytorch-llmcompressor-cuda-py312-rhel9", "product": "Red Hat OpenShift AI (RHOAI)", "vendor": "Red Hat" }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:openshift_ai" ], "defaultStatus": "affected", "packageName": "rhoai/odh-workbench-jupyter-pytorch-rocm-py312-rhel9", "product": "Red Hat OpenShift AI (RHOAI)", "vendor": "Red Hat" }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:openshift_ai" ], "defaultStatus": "affected", "packageName": "rhoai/odh-workbench-jupyter-tensorflow-cuda-py312-rhel9", "product": "Red Hat OpenShift AI (RHOAI)", "vendor": "Red Hat" }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:openshift_ai" ], "defaultStatus": "affected", "packageName": "rhoai/odh-workbench-jupyter-tensorflow-rocm-py312-rhel9", "product": "Red Hat OpenShift AI (RHOAI)", "vendor": "Red Hat" }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:openshift_ai" ], "defaultStatus": "affected", "packageName": "rhoai/odh-workbench-jupyter-trustyai-cpu-py312-rhel9", "product": "Red Hat OpenShift AI (RHOAI)", "vendor": "Red Hat" } ], "datePublic": "2026-05-05T21:29:31.323Z", "descriptions": [ { "lang": "en", "value": "A flaw was found in Jupyter Server. The Origin header validation, which uses Python's `re.match()` function, does not correctly validate incoming origins against allowed patterns. This allows a remote attacker to bypass Cross-Origin Resource Sharing (CORS) restrictions by crafting a malicious domain that partially matches a trusted one. Consequently, the attacker can make unauthorized cross-origin requests to the Jupyter Server API from an untrusted site, potentially leading to sensitive information disclosure or other unauthorized actions." } ], "metrics": [ { "other": { "content": { "namespace": "https://access.redhat.com/security/updates/classification/", "value": "Important" }, "type": "Red Hat severity rating" } }, { "cvssV3_1": { "attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 7.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N", "version": "3.1" }, "format": "CVSS" } ], "problemTypes": [ { "descriptions": [ { "cweId": "CWE-625", "description": "Permissive Regular Expression", "lang": "en", "type": "CWE" } ] } ], "references": [ { "tags": [ "vdb-entry", "x_refsource_REDHAT" ], "url": "https://access.redhat.com/security/cve/CVE-2026-40110" }, { "name": "RHBZ#2466912", "tags": [ "issue-tracking", "x_refsource_REDHAT" ], "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2466912" }, { "tags": [ "x_sadp-csaf-vex" ], "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40110.json" }, { "tags": [ "vendor-advisory", "x_refsource_REDHAT" ], "url": "https://access.redhat.com/errata/RHSA-2026:43038" } ], "solutions": [ { "lang": "en", "value": "RHSA-2026:43038: Red Hat Migration Toolkit for Applications 8.2" } ], "timeline": [ { "lang": "en", "time": "2026-05-05T22:01:09.643Z", "value": "Reported to Red Hat." }, { "lang": "en", "time": "2026-05-05T21:29:31.323Z", "value": "Made public." } ], "title": "jupyter-server: Jupyter Server: Cross-Origin Resource Sharing (CORS) bypass via improper Origin header validation", "workarounds": [ { "lang": "en", "value": "Administrators should review and update the `allow_origin_pat` configuration in Jupyter Server to use a more precise regular expression. Ensure the pattern explicitly anchors to the end of the string (e.g., by adding `$` to the end of the regex) to prevent partial domain matches. After modifying the configuration, the Jupyter Server service must be restarted for the changes to take effect." } ], "x_adpType": "supplier", "x_generator": { "engine": "sadp-cli 1.0.0" }, "providerMetadata": { "orgId": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "shortName": "redhat-SADP", "dateUpdated": "2026-07-22T12:08:40.428Z" } } ] } }