Privilege Escalation in open-webui (CVE-2026-45395)
Summary
Vulnerability in open-webui (CVE-2026-45395). Successful exploitation can lead to full system takeover. Exploitable via POST /api/v1/tools/id/{id}/update. Mitigation: upgrade to 0.9.5 or later.
Original description
The description as published by the source.
Summary
The tool update endpoint (POST /api/v1/tools/id/{id}/update) is missing the workspace.tools permission check that is present on the tool create endpoint. This allows a user who has been explicitly denied tool management capabilities ( and who the administrator considers untrusted for code execution ) to replace a tool's server-side Python content and trigger execution, bypassing the intended workspace.tools security boundary.
Open WebUI's security policy correctly states that workspace.tools is the trust boundary for code execution: "Granting a user the ability to create Tools is equivalent to giving them shell access to the server." This vulnerability breaks that boundary. A write access grant on a single tool is sufficient to bypass workspace.tools entirely.
This is not a report about exec() being unsandboxed (that is acknowledged as intended behavior). This is a report about a missing authorization check that allows an untrusted user to reach the exec() sink that should be gated behind workspace.tools.
Root Cause
The create and update endpoints for tools have asymmetric authorization checks. The create endpoint enforces the workspace.tools permission; the update endpoint does not.
Create endpoint, enforces workspace.tools
File: backend/open_webui/routers/tools.py, lines 326-345
@router.post('/create', response_model=Optional[ToolResponse])
async def create_new_tools(
request: Request,…
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-2026-45395 has been found in open-webui.
Attackers can target a specific entry point like POST /api/v1/tools/id/{id}/update over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 7.2/10.
What to do: upgrade open-webui to 0.9.5 or later.
If unsure, ask your IT team or search "open-webui CVE-2026-45395" on the vendor's site.
CVE-2026-45395 (open-webui) — CWE-269 / CVSS v3 7.2
Attack vector: remote (network-reachable) / no user interaction
Attack surface: POST /api/v1/tools/id/{id}/update / POST /tools/create / POST /api/v1/tools/id/poc_rce_2/update / POST /poc2
Patched: 0.9.5 — 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-269) exists in open-webui. Attackers reach the vulnerable code path via POST /api/v1/tools/id/{id}/update.
Check the vendor advisory for the affected versions of open-webui. Attack surface: POST /api/v1/tools/id/{id}/update / POST /tools/create / POST /api/v1/tools/id/poc_rce_2/update / POST /poc2.
Severity: High (CVSS 7.2/10). Successful exploitation can lead to full system takeover.
Update to 0.9.5.
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/tools/id/{id}/update 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/tools/id/{id}/update' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /api/v1/tools/id/{id}/update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 0.9.5ステージング環境で 0.9.5 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/tools/id/{id}/update 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
- exploit github.com
- package github.com
- web github.com
- web github.com