{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-104851", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-10-02T14:38:43.244Z", "datePublished": "2026-10-02T16:36:48.513Z", "dateUpdated": "2026-10-02T16:36:48.513Z"}, "containers": {"cna": {"title": "fsspec: Server-Side Template Injection in ReferenceFileSystem leads to Remote Code Execution", "problemTypes": [{"descriptions": [{"cweId": "CWE-94", "lang": "en", "description": "CWE-94: Improper Control of Generation of Code ('Code Injection')", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-1336", "lang": "en", "description": "CWE-1336: Improper Neutralization of Special Elements Used in a Template Engine", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/fsspec/filesystem_spec/security/advisories/GHSA-27vj-qcqg-25rc", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/fsspec/filesystem_spec/security/advisories/GHSA-27vj-qcqg-25rc"}, {"name": "https://github.com/fsspec/filesystem_spec/pull/2029", "tags": ["x_refsource_MISC"], "url": "https://github.com/fsspec/filesystem_spec/pull/2029"}, {"name": "https://github.com/fsspec/filesystem_spec/pull/2039", "tags": ["x_refsource_MISC"], "url": "https://github.com/fsspec/filesystem_spec/pull/2039"}, {"name": "https://github.com/fsspec/filesystem_spec/commit/86438783f93b1398ef245b92f0e6063b445b611c", "tags": ["x_refsource_MISC"], "url": "https://github.com/fsspec/filesystem_spec/commit/86438783f93b1398ef245b92f0e6063b445b611c"}, {"name": "https://github.com/fsspec/filesystem_spec/commit/a1c16ab3f07f354aa371c38f7b1b07ea7fd4c5c8", "tags": ["x_refsource_MISC"], "url": "https://github.com/fsspec/filesystem_spec/commit/a1c16ab3f07f354aa371c38f7b1b07ea7fd4c5c8"}, {"name": "https://github.com/fsspec/filesystem_spec/releases/tag/2026.6.0", "tags": ["x_refsource_MISC"], "url": "https://github.com/fsspec/filesystem_spec/releases/tag/2026.6.0"}], "affected": [{"vendor": "fsspec", "product": "filesystem_spec", "versions": [{"version": ">= 0.9.0, < 2026.6.0", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-10-02T16:36:48.513Z"}, "descriptions": [{"lang": "en", "value": "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."}], "source": {"advisory": "GHSA-27vj-qcqg-25rc", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "filesystem_spec", "vendor": "fsspec", "versions": [{"status": "affected", "version": ">= 0.9.0, < 2026.6.0"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-104851", "lastModified": "2026-10-02T17:17:03.763", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 5.9, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-10-02T17:17:03.763", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/fsspec/filesystem_spec/commit/86438783f93b1398ef245b92f0e6063b445b611c"}, {"source": "security-advisories@github.com", "url": "https://github.com/fsspec/filesystem_spec/commit/a1c16ab3f07f354aa371c38f7b1b07ea7fd4c5c8"}, {"source": "security-advisories@github.com", "url": "https://github.com/fsspec/filesystem_spec/pull/2029"}, {"source": "security-advisories@github.com", "url": "https://github.com/fsspec/filesystem_spec/pull/2039"}, {"source": "security-advisories@github.com", "url": "https://github.com/fsspec/filesystem_spec/releases/tag/2026.6.0"}, {"source": "security-advisories@github.com", "url": "https://github.com/fsspec/filesystem_spec/security/advisories/GHSA-27vj-qcqg-25rc"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-94"}, {"lang": "en", "value": "CWE-1336"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{"created": "2026-10-02T17:30:18.091469+00:00", "updated": "2026-10-02T17:30:18.091483+00:00", "vendors": []}