Vulnerability in open-webui (CVE-2026-70487)
Summary
Vulnerability in open-webui (CVE-2026-70487). Confidential information can be exposed externally. Exploitable via builtin_tools. Mitigation: upgrade to 0.11.0 or later.
Original description
The description as published by the source.
Summary
Open WebUI lets a client define a model inline on a chat request instead of selecting a saved workspace model. The knowledge attached to such an inline model was used as-is, without checking that the caller can read what it points at. Any authenticated user who knows another user's file id could therefore have the builtin knowledge tools return that file's indexed content back to them.
Preconditions
Authenticated user of any role, no admin rights needed. The request must carry a session id and use native function calling, which is the default (only function_calling: legacy opts out), and the model's builtin_tools capability must not be disabled (default enabled). The attacker must already know the target file's id; ids are UUIDs and are not enumerable through this path. No admin setting needs to be turned on: enabling Direct Connections is not required for the backend to accept an inline model. Knowledge bases attached this way were never affected, their own access grants were enforced on every path.
Impact
An authenticated user could read the indexed chunks of another user's or group's file, a cross-user confidentiality loss limited to files whose ids the attacker already holds. It is read-only: nothing is modified or deleted, knowledge-base permissions are unaffected, and saved workspace models were already validated at creation time.
Fix
Fixed in 0.11.0 by commit 305880f2e. An inline model's attached knowledge is filtered against the caller's rea…
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-2026-70487 has been found in open-webui.
Attackers can target a specific entry point like builtin_tools over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 5.3/10.
What to do: upgrade open-webui to 0.11.0 or later.
If unsure, ask your IT team or search "open-webui CVE-2026-70487" on the vendor's site.
CVE-2026-70487 (open-webui) — CWE-862 / CVSS v3 5.3
Attack vector: remote (network-reachable) / no user interaction
Attack surface: builtin_tools
Patched: 0.11.0 — 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-862) exists in open-webui. Attackers reach the vulnerable code path via builtin_tools.
Check the vendor advisory for the affected versions of open-webui. Attack surface: builtin_tools.
Severity: Medium (CVSS 5.3/10). Confidential information can be exposed externally.
Update to 0.11.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. 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。 -
2Apply patch patch
Upgrade open-webui to 0.11.0ステージング環境で 0.11.0 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を含めること。
-
3Post-deployment verification verify
Confirm patched version is live in production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。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- package pypi.org
- web github.com
- web github.com
- web github.com