{"id":"CVE-2026-54567","title":"Flask-Reuploaded provides file uploads for Flask","summary":"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 hel…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-178","CWE-434"],"vendor":"jugmac00","product":"flask-reuploaded","affected":["flask-reuploaded < 1.6.0"],"patched":["Flask-Reuploaded 1.6.0"],"published":"2026-09-14","updated":"2026-09-16","sourceUpdated":"2026-09-16T16:17:09.010","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-54567","references":[{"url":"https://github.com/jugmac00/flask-reuploaded/commit/5ded76092429c6eb8a4af941b14fbde40a38fff4","label":"security-advisories@github.com"},{"url":"https://github.com/jugmac00/flask-reuploaded/pull/186","label":"security-advisories@github.com"},{"url":"https://github.com/jugmac00/flask-reuploaded/security/advisories/GHSA-937x-gpqr-72gg","label":"security-advisories@github.com"},{"url":"https://github.com/jugmac00/flask-reuploaded/security/advisories/GHSA-937x-gpqr-72gg","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://github.com/advisories/GHSA-937x-gpqr-72gg"}],"tags":["nvd","cve.org","ghsa","pip","exploit-available"],"epss":0.00584,"epssPercentile":0.46355,"aliases":["GHSA-937x-gpqr-72gg"],"ecosystem":"pip","exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"total","timestamp":"2026-09-16T15:22:17.514494Z"},"ingestedAt":"2026-07-17T20:15:43.245Z","slug":"CVE-2026-54567","body":"## Overview\n\nFlask-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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-54567)\n\nAffected packages:\n\n- `Flask-Reuploaded <= 1.5.0`\n\nPatched in:\n\n- `Flask-Reuploaded 1.6.0`\n\nSource: https://github.com/advisories/GHSA-937x-gpqr-72gg","depth":"midnight","depthScore":53,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":205377,"id":"CVE-2026-54567","ts":1789574381133,"field":"exploit_available","old":"false","new":"true"}]}