{"cve":"CVE-2026-102598","nvd":{"published":"2026-09-29T16:17:06.010","modified":"2026-09-30T19:38:27.293","status":"Awaiting Analysis","description":"Werkzeug is a comprehensive WSGI web application library. Prior to 3.1.9, the safe_join function used by send_from_directory can allow a NUL: special-device path because safe_join checks the Windows device name without first removing an empty NTFS ADS marker. The trigger is that an application runs on Windows with NTFS and serves a user-specified path ending in a special device name such as NUL:. The attack mechanism is that a requested path ends in a Windows special device name with an empty ADS marker. The impact is that the special device opens successfully and the file read hangs indefinitely. This issue is fixed in version 3.1.9.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","score":6.3},"cvss_v3":null,"cwes":["CWE-67"],"references":["https://github.com/pallets/werkzeug/commit/8d77320bcdf3a34941ec06dcf16b03c065cd21b6","https://github.com/pallets/werkzeug/pull/3309","https://github.com/pallets/werkzeug/releases/tag/3.1.9","https://github.com/pallets/werkzeug/security/advisories/GHSA-g6x2-hccm-hh4m"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:56:48.555445741+00:00"},"epss":{"cve":"CVE-2026-102598","score":0.0037,"percentile":0.30619,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-g6x2-hccm-hh4m","url":"https://osv.dev/vulnerability/GHSA-g6x2-hccm-hh4m","summary":"Werkzeug safe_join() allows Windows special device names","modified":"2026-10-15T14:56:11.020811348Z","packages":[{"ecosystem":"PyPI","name":"werkzeug","purl":"pkg:pypi/werkzeug","ranges":["<3.1.9"],"fixed":["3.1.9"]}]},{"id":"PYSEC-2026-4312","url":"https://osv.dev/vulnerability/PYSEC-2026-4312","summary":"Werkzeug safe_join() allows Windows special device names","modified":"2026-10-15T14:45:14.716393013Z","packages":[{"ecosystem":"PyPI","name":"werkzeug","purl":"pkg:pypi/werkzeug","ranges":["<3.1.9"],"fixed":["3.1.9"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}