CVE-2026-54567

{"id": "CVE-2026-54567", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 1.6}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "jugmac00", "product": "flask-reuploaded", "versions": [{"status": "affected", "version": "< 1.6.0"}]}]}], "published": "2026-09-14T18:17:53.547", "references": [{"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", "source": "security-advisories@github.com"}], "vulnStatus": "Received", "weaknesses": [{"type": "Primary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-178"}, {"lang": "en", "value": "CWE-434"}]}], "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."}], "lastModified": "2026-09-14T18:17:53.547", "sourceIdentifier": "security-advisories@github.com"}