Sign in Sign up
JA · EN · FR
SecPulse
Categories
CVE-2026-88000 medium CVSS 6.5

Vulnerability in open-webui (CVE-2026-88000)

Summary

Vulnerability in open-webui (CVE-2026-88000). Risk of unauthorized operations or information disclosure. Exploitable via DELETE /api/v1/chats/{id}/messages/{message_id}. Mitigation: upgrade to 0.11.1 or later.

Original description

The description as published by the source.

Summary

Chat histories are stored as an unvalidated JSON object. After a message is deleted, the code that picks the chat's new current message walked down the childrenIds links without recording where it had already been. Any account with the default user role could store a chat whose messages list each other as children, then delete a message from it, and the walk would run forever. That walk runs on the server's request loop, so it blocks every other user's requests until the process is killed.

Preconditions

One account with the default user role. No administrator rights, no additional permissions, no configuration change and no non-default setting: creating and deleting chats is available to every user out of the box. The attack runs entirely against the attacker's own chat, so no knowledge of any other user's data is needed. Versions before 0.10.0 are unaffected because neither the message-deletion endpoint nor the affected code existed.

Impact

The walk is synchronous and runs on the asyncio event loop, so while it spins, every request from every user is blocked, including unauthenticated /health and administrator endpoints. External health checks and orchestrator liveness probes fail alongside the UI. This is a pure CPU pin with no list growth, so a worker consumes one full core with flat memory and has to be killed rather than being reclaimed by an out-of-memory kill. The work is not cancelled when the client disconnects, so a single fire-and-forget…

Source: NIST National Vulnerability Database 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-2026-88000 has been found in open-webui.
Attackers can target a specific entry point like DELETE /api/v1/chats/{id}/messages/{message_id} over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 6.5/10.
What to do: upgrade open-webui to 0.11.1 or later.
If unsure, ask your IT team or search "open-webui CVE-2026-88000" on the vendor's site.

CVE-2026-88000 (open-webui) — CWE-835 / CVSS v3 6.5
Attack vector: remote (network-reachable) / no user interaction
Attack surface: DELETE /api/v1/chats/{id}/messages/{message_id} / POST /api/v1/chats/new / DELETE /api/v1/chats/{id}/messages/C / GET /health
Patched: 0.11.1 — 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.

❓ What is the problem

A vulnerability (CWE-835) exists in open-webui. Attackers reach the vulnerable code path via DELETE /api/v1/chats/{id}/messages/{message_id}.

📍 Affected scope

Check the vendor advisory for the affected versions of open-webui. Attack surface: DELETE /api/v1/chats/{id}/messages/{message_id} / POST /api/v1/chats/new / DELETE /api/v1/chats/{id}/messages/C / GET /health.

🔥 Severity

Severity: Medium (CVSS 6.5/10). Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 0.11.1.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual DELETE /api/v1/chats/{id}/messages/{message_id} 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

  1. 1
    Identify 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。

  2. 2
    Hunt for indicators of compromise detect 
    grep 'DELETE /api/v1/chats/{id}/messages/{message_id}' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'

    アクセスログで DELETE /api/v1/chats/{id}/messages/{message_id} 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。

  3. 3
    Apply patch patch 
    Upgrade open-webui to 0.11.1

    ステージング環境で 0.11.1 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。

  4. 4
    Post-deployment verification verify 
    Replay attack against DELETE /api/v1/chats/{id}/messages/{message_id} 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

pip open-webui
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.11.1"}]}]

References

We use cookies for analytics and ad measurement. This setting applies to all Game co., Ltd. sites. Details