{"id":"CVE-2026-104851","revision":null,"records":[{"revision":"f66b1cfeff8f4708b7c7aa3eae4681a9","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-104851","aliases":[],"title":"fsspec: Server-Side Template Injection in ReferenceFileSystem leads to Remote Code Execution","description":"fsspec is a specification and Python implementation framework for filesystem interfaces. From 0.9.0 until 2026.6.0, fsspec.implementations.reference.ReferenceFileSystem evaluates fields from Kerchunk reference JSON documents through unrestricted jinja2.Template(...).render(...) calls in _process_references1._render_jinja, _process_templates, and _process_gen in fsspec/implementations/reference.py. A document supplied inline or fetched from an attacker-controlled URL can provide template expressions that execute Python code when the reference filesystem is opened, including through consumers such as xarray, before referenced data is read. The _process_gen path is reached whenever a document includes a gen array, while the other paths depend on template-related options and values. This issue is fixed in version 2026.6.0.","state":0,"publishedAt":"2026-10-02T16:36:48.513+00:00","modifiedAt":"2026-10-05T20:03:36.502+00:00","affected":[{"ecosystem":"Vendor product","name":"filesystem_spec","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"fsspec\",\n                    \"product\": \"filesystem_spec\",\n                    \"versions\": [\n                        {\n                            \"version\": \">= 0.9.0, < 2026.6.0\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","score":8.8,"severity":"HIGH"}],"references":["https://github.com/fsspec/filesystem_spec/security/advisories/GHSA-27vj-qcqg-25rc","https://github.com/fsspec/filesystem_spec/pull/2029","https://github.com/fsspec/filesystem_spec/pull/2039","https://github.com/fsspec/filesystem_spec/commit/86438783f93b1398ef245b92f0e6063b445b611c","https://github.com/fsspec/filesystem_spec/commit/a1c16ab3f07f354aa371c38f7b1b07ea7fd4c5c8","https://github.com/fsspec/filesystem_spec/releases/tag/2026.6.0"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-104851","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-104851","identifiers":["CVE-2026-104851"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-11-11T15:59:29.1371819+00:00","complete":true,"records":1779,"lastAttemptAt":"2026-11-11T15:59:29.1371819+00:00","lastSuccessAt":"2026-11-11T15:59:29.3319702+00:00","error":null,"lastVerifiedAt":"2026-11-11T15:59:29.3319715+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-de3b77103708811b6494d2ff7c979037d73ae579742cd1649a5c765137ae5083-f7a27b6686d027a29d541c1a67c85e77c8818c1542bd9e626ca104d5a08b6cff","complete":true,"records":424160,"lastAttemptAt":"2026-11-11T15:57:33.081355+00:00","lastSuccessAt":"2026-11-11T15:57:32.9249839+00:00","error":null,"lastVerifiedAt":"2026-11-11T15:57:33.081355+00:00","snapshotPublishedAt":"2026-11-11T15:27:38+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-fbe6382b6d1e4810ad598ca4b39b1839","complete":false,"records":13759,"lastAttemptAt":"2026-11-11T16:11:34.900804+00:00","lastSuccessAt":"2026-11-11T16:11:34.895+00:00","error":"8 identifier lookups failed; latest failures include HTTP 403. Other identifiers were checked independently.","lastVerifiedAt":"2026-11-11T16:11:34.895+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13527,"expectedIdentifiers":13813,"failedIdentifiers":8},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-11T15:59:29.1371819+00:00","complete":true,"records":1097,"lastAttemptAt":"2026-11-11T15:59:29.1371819+00:00","lastSuccessAt":"2026-11-11T15:59:29.3328867+00:00","error":null,"lastVerifiedAt":"2026-11-11T15:59:29.332887+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-83d5ee721aa54b298ac0e478691d5c53","complete":true,"records":13753,"lastAttemptAt":"2026-11-11T15:59:30.4109764+00:00","lastSuccessAt":"2026-11-11T15:59:30.407+00:00","error":null,"lastVerifiedAt":"2026-11-11T15:59:30.407+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":"2026-11-11T15:59:28.9781944+00:00","lastSuccessAt":"2026-11-11T04:27:43.6877707+00:00","error":null,"lastVerifiedAt":"2026-11-11T15:59:28.9781944+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":"2026-11-11T15:57:33.229994+00:00","lastSuccessAt":"2026-11-11T02:36:58.1276999+00:00","error":null,"lastVerifiedAt":"2026-11-11T15:57:33.229994+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":"2026-11-11T15:59:29.0795742+00:00","lastSuccessAt":"2026-11-11T13:00:02.5446881+00:00","error":null,"lastVerifiedAt":"2026-11-11T15:59:29.0795742+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-eb69eb75f2b568fd8be458efa2db8e11aac201724ba0b44fa3f79c386f195e15","complete":true,"records":231668,"lastAttemptAt":"2026-11-11T15:59:28.847182+00:00","lastSuccessAt":"2026-11-11T15:59:27.3458308+00:00","error":null,"lastVerifiedAt":"2026-11-11T15:59:28.847182+00:00","snapshotPublishedAt":"2026-11-11T15:33:06+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}