{"id":"CVE-2026-102830","revision":null,"records":[{"revision":"9bc97422d23f4388a26a51ab964deef2","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-102830","aliases":[],"title":"JupyterLab: Cross-site scripting (XSS) in JupyterLab via crafted language package (jupyterlab.json)","description":"JupyterLab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. From JupyterLab 3.0.0 until 4.5.11 and 4.6.4, and in JupyterLite Core 0.8.3 and earlier, the Plural-Forms header in a selected third-party language pack can append JavaScript after a valid plural rule because prefix-only regular-expression validation accepts a matching prefix without requiring the entire header to match. JupyterLab passes the accepted expression to new Function, so loading the catalogue and translating a plural string executes the appended code in the authenticated JupyterLab origin. Where Jupyter Server kernels, terminals, and APIs are exposed, the code can use authenticated server APIs to read or modify files and run code. Impact is much more limited in JupyterLite because it typically lacks most exposed Jupyter Server surfaces. The default English locale is unaffected because it does not load a translation catalogue. This issue is fixed in JupyterLab 4.5.11 and 4.6.4 and JupyterLite Core 0.8.4.","state":0,"publishedAt":"2026-09-29T18:53:19.055+00:00","modifiedAt":"2026-09-29T20:00:25.547+00:00","affected":[{"ecosystem":"Vendor product","name":"jupyterlab","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"jupyterlab\",\n                    \"product\": \"jupyterlab\",\n                    \"versions\": [\n                        {\n                            \"version\": \">= 3.0.0, < 4.5.11\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \">= 4.6.0, < 4.6.4\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"jupyterlite-core","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"jupyterlab\",\n                    \"product\": \"jupyterlite-core\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 0.8.4\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N","score":6.8,"severity":"MEDIUM"}],"references":["https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-3jqq-pw4j-pqcj","https://github.com/jupyterlab/jupyterlab/commit/985a3223cd77fd4f991cd90066342a90711d70f6","https://github.com/jupyterlab/jupyterlab/commit/de324ae91346c713c4f5e5485f97b6e914e0f774","https://github.com/jupyterlab/jupyterlab/commit/f9de43dc565a1118120d466117f877a189a4ce90","https://github.com/jupyterlab/jupyterlab/releases/tag/v4.5.11","https://github.com/jupyterlab/jupyterlab/releases/tag/v4.6.4"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-102830","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-102830","identifiers":["CVE-2026-102830"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-11-12T05:58:40.9203184+00:00","complete":true,"records":1779,"lastAttemptAt":"2026-11-12T05:58:40.9203184+00:00","lastSuccessAt":"2026-11-12T05:58:41.095627+00:00","error":null,"lastVerifiedAt":"2026-11-12T05:58:41.0956282+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"cve-program","scope":"Official CVE Program baseline and cumulative hourly delta; all vendors, published and rejected records","generation":"cve-64752486c567b55b31fb0d7225f5222bcd0019564ac0ac5f0649e242c7b19299-88a69dfec4d1b83d929ca06b957aa3a4484cd80632df1e27cf4c312635b2bedd","complete":true,"records":424594,"lastAttemptAt":"2026-11-12T05:56:53.4810169+00:00","lastSuccessAt":"2026-11-12T05:56:53.4611758+00:00","error":null,"lastVerifiedAt":"2026-11-12T05:56:53.4810169+00:00","snapshotPublishedAt":"2026-11-12T05:28:30+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"euvd","scope":"Rolling EUVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-dfa2c4aaec6f4aecad791663dd265c1b","complete":true,"records":13760,"lastAttemptAt":"2026-11-12T06:00:32.7256045+00:00","lastSuccessAt":"2026-11-12T06:00:32.721+00:00","error":null,"lastVerifiedAt":"2026-11-12T06:00:32.721+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13813,"expectedIdentifiers":13813,"failedIdentifiers":0},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-12T05:58:40.9203184+00:00","complete":true,"records":1097,"lastAttemptAt":"2026-11-12T05:58:40.9203184+00:00","lastSuccessAt":"2026-11-12T05:58:41.0963887+00:00","error":null,"lastVerifiedAt":"2026-11-12T05:58:41.0963888+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-6b3a361b3e0f452d8ff70bd272635b35","complete":true,"records":13760,"lastAttemptAt":"2026-11-12T05:59:00.2510884+00:00","lastSuccessAt":"2026-11-12T05:59:00.248+00:00","error":null,"lastVerifiedAt":"2026-11-12T05:59:00.248+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13813,"expectedIdentifiers":13813,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-3562b6c78fd1bd0f0b55daf66a0926ae24f65e462df7f6d928caad458fc696bf","complete":true,"records":9947,"lastAttemptAt":"2026-11-12T05:58:40.8633143+00:00","lastSuccessAt":"2026-11-11T04:27:43.6877707+00:00","error":null,"lastVerifiedAt":"2026-11-12T05:58:40.8633143+00:00","snapshotPublishedAt":"2026-11-11T03:32:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-456002455e0ab94bb92c95476d4e6d175c104cd594749982afd96c893728ecbc","complete":true,"records":2010,"lastAttemptAt":"2026-11-12T05:56:53.625749+00:00","lastSuccessAt":"2026-11-11T02:36:58.1276999+00:00","error":null,"lastVerifiedAt":"2026-11-12T05:56:53.625749+00:00","snapshotPublishedAt":"2026-11-11T01:17:51+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-baa8362b4daf9e5f39d5563775a55935e7b442c0735d33274a921579ce4a0d66","complete":true,"records":3093,"lastAttemptAt":"2026-11-12T05:58:40.8782632+00:00","lastSuccessAt":"2026-11-11T13:00:02.5446881+00:00","error":null,"lastVerifiedAt":"2026-11-12T05:58:40.8782632+00:00","snapshotPublishedAt":"2026-11-11T12:47:47+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-eb5176d73e87a862c4cae7484f3fd31f7d170139114b3e99e25926d661f6435b","complete":true,"records":231700,"lastAttemptAt":"2026-11-12T05:58:40.7363027+00:00","lastSuccessAt":"2026-11-12T05:58:39.2691741+00:00","error":null,"lastVerifiedAt":"2026-11-12T05:58:40.7363027+00:00","snapshotPublishedAt":"2026-11-12T05:48:10+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}