Vulnerability in open-webui (CVE-2026-45396)
Summary
Vulnerability in open-webui (CVE-2026-45396). Risk of unauthorized operations or information disclosure. Exploitable via POST /api/v1/evaluations/feedback. Mitigation: upgrade to 0.9.0 or later.
Original description
The description as published by the source.
Mass Assignment in Feedback Creation Allows User ID Spoofing and Evaluation Data Manipulation
Summary
The POST /api/v1/evaluations/feedback endpoint in Open WebUI v0.9.2 is vulnerable to mass assignment via FeedbackForm, which uses model_config = ConfigDict(extra='allow'). Due to an insecure dictionary merge order in insert_new_feedback(), an authenticated attacker can inject a user_id 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.
Details
The vulnerability exists in two layers:
1. Model Layer — Insecure Dict Merge Order
File: backend/open_webui/models/feedbacks.py, lines 148–160
async def insert_new_feedback(
self, user_id: str, form_data: FeedbackForm, db: Optional[AsyncSession] = None
) -> Optional[FeedbackModel]:
async with get_async_db_context(db) as db:
id = str(uuid.uuid4())
feedback = FeedbackModel(
**{
'id': id,
'user_id': user_id, # ← Server-set from auth token
'version': 0,
**form_data.model_dump(), # ← OVERWRITES 'id', 'user_id', 'version'
'created_at': int(time.time()),
'updated_at': int(time.time()),
}
)
In Python, when a dictionary literal contains duplicate keys, the *last value wins…
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-45396 has been found in open-webui.
Attackers can target a specific entry point like POST /api/v1/evaluations/feedback over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.4/10.
What to do: upgrade open-webui to 0.9.0 or later.
If unsure, ask your IT team or search "open-webui CVE-2026-45396" on the vendor's site.
CVE-2026-45396 (open-webui) — CWE-915 / CVSS v3 5.4
Attack vector: remote (network-reachable) / no user interaction
Attack surface: POST /api/v1/evaluations/feedback / GET /api/v1/evaluations/feedbacks/export / GET /api/v1/evaluations/feedbacks/all / FeedbackForm
Patched: 0.9.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-915) exists in open-webui. Attackers reach the vulnerable code path via POST /api/v1/evaluations/feedback.
Check the vendor advisory for the affected versions of open-webui. Attack surface: POST /api/v1/evaluations/feedback / GET /api/v1/evaluations/feedbacks/export / GET /api/v1/evaluations/feedbacks/all / FeedbackForm.
Severity: Medium (CVSS 5.4/10). Risk of unauthorized operations or information disclosure.
Update to 0.9.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual POST /api/v1/evaluations/feedback requests with malformed payloads or SQL meta-characters. Run grep -r 'open-webui' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'open-webui' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
open-webuiを grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'POST /api/v1/evaluations/feedback' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /api/v1/evaluations/feedbackへの異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Apply patch patch
Upgrade open-webui to 0.9.0ステージング環境で 0.9.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスと、Step 2 で見つけた異常検知の続報チェックを含めること。
-
4Post-deployment verification verify
Replay attack against POST /api/v1/evaluations/feedback on staging to confirm patch closes the vectorパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com