{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-54567", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-06-15T19:15:27.343Z", "datePublished": "2026-09-14T17:15:49.272Z", "dateUpdated": "2026-09-14T17:16:08.820Z"}, "containers": {"cna": {"title": "Flask-Reuploaded: Extension-denylist bypass via case-folding asymmetry in name-override path (incomplete-fix variant of CVE-2026-27641)", "problemTypes": [{"descriptions": [{"cweId": "CWE-178", "lang": "en", "description": "CWE-178: Improper Handling of Case Sensitivity", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-434", "lang": "en", "description": "CWE-434: Unrestricted Upload of File with Dangerous Type", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/jugmac00/flask-reuploaded/security/advisories/GHSA-937x-gpqr-72gg", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/jugmac00/flask-reuploaded/security/advisories/GHSA-937x-gpqr-72gg"}, {"name": "https://github.com/jugmac00/flask-reuploaded/pull/186", "tags": ["x_refsource_MISC"], "url": "https://github.com/jugmac00/flask-reuploaded/pull/186"}, {"name": "https://github.com/jugmac00/flask-reuploaded/commit/5ded76092429c6eb8a4af941b14fbde40a38fff4", "tags": ["x_refsource_MISC"], "url": "https://github.com/jugmac00/flask-reuploaded/commit/5ded76092429c6eb8a4af941b14fbde40a38fff4"}], "affected": [{"vendor": "jugmac00", "product": "flask-reuploaded", "versions": [{"version": "< 1.6.0", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-09-14T17:16:08.820Z"}, "descriptions": [{"lang": "en", "value": "Flask-Reuploaded provides file uploads for Flask. From 1.5.0 until 1.6.0, UploadSet.save(storage, name=...) in src/flask_uploads/flask_uploads.py applies lowercase_ext to the default upload path but uses the case-preserving extension helper for a caller-supplied name before extension_allowed evaluates an AllExcept denylist. An attacker who controls the name override can use a mixed-case dangerous extension to bypass a lowercase denylist and store the file in the served upload directory. Exploitation requires a denylist configuration, a user-influenced name override, and a deployment that resolves or executes extensions case-insensitively; pure allowlists remain protected and path containment is not bypassed. On an execution-capable upload directory, the stored file can execute with the web server's privileges and affect confidentiality, integrity, and availability. This issue is fixed in version 1.6.0."}], "source": {"advisory": "GHSA-937x-gpqr-72gg", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "flask-reuploaded", "vendor": "jugmac00", "versions": [{"status": "affected", "version": "< 1.6.0"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Flask-Reuploaded provides file uploads for Flask. From 1.5.0 until 1.6.0, UploadSet.save(storage, name=...) in src/flask_uploads/flask_uploads.py applies lowercase_ext to the default upload path but uses the case-preserving extension helper for a caller-supplied name before extension_allowed evaluates an AllExcept denylist. An attacker who controls the name override can use a mixed-case dangerous extension to bypass a lowercase denylist and store the file in the served upload directory. Exploitation requires a denylist configuration, a user-influenced name override, and a deployment that resolves or executes extensions case-insensitively; pure allowlists remain protected and path containment is not bypassed. On an execution-capable upload directory, the stored file can execute with the web server's privileges and affect confidentiality, integrity, and availability. This issue is fixed in version 1.6.0."}], "id": "CVE-2026-54567", "lastModified": "2026-09-14T18:17:53.547", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.6, "impactScore": 5.9, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-09-14T18:17:53.547", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/jugmac00/flask-reuploaded/commit/5ded76092429c6eb8a4af941b14fbde40a38fff4"}, {"source": "security-advisories@github.com", "url": "https://github.com/jugmac00/flask-reuploaded/pull/186"}, {"source": "security-advisories@github.com", "url": "https://github.com/jugmac00/flask-reuploaded/security/advisories/GHSA-937x-gpqr-72gg"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-178"}, {"lang": "en", "value": "CWE-434"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{}