Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, the POST /api/v1/evaluations/feedback endpoint in Open WebUI v0.9.2 is vulnerable to mass assignment via FeedbackForm, which uses modelconfig = ConfigDict(extra='allow'). Due to an insecure dictionary merge order in insertnewfeedback(), an authenticated attacker can inject a userid field in the request body that overwrites the server-derived value, creating feedback records attributed to any arbitrary user. This corrupts the model evaluation leaderboard (Elo ratings) and enables identity spoofing. This vulnerability is fixed in 0.9.5.
{
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-915"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45396.json"
}{
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "0.9.5"
}
],
"cpe": "cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*",
"source": [
"AFFECTED_FIELD",
"CPE_RANGE"
]
}