Privilege Escalation in open-webui (CVE-2026-87998)
Summary
Vulnerability in open-webui (CVE-2026-87998). Data can be tampered with by attackers. Exploitable via DELETE /api/v1/knowledge/{id}/delete.. Mitigation: upgrade to 0.11.1 or later.
Original description
The description as published by the source.
Summary
External knowledge connections are created and owned by administrators, and are shared by every external knowledge base bound to them. Deleting an external knowledge base also removed that connection from the instance configuration, with no check on the caller's role and no check for other knowledge bases still using it. Any authenticated user holding a write grant on a single external knowledge base could therefore wipe a shared connection that other knowledge bases depend on, and the dedicated administrator route for deleting a connection explicitly refuses that same operation while the connection is still in use.
Preconditions
The deployment uses external knowledge bases, backed by the qdrant, milvus or pgvector external providers. Instances with only local knowledge bases are not affected.
An administrator created at least one external connection and at least one external knowledge base bound to it. Both of those actions are admin-only.
The attacker is an ordinary authenticated user holding a write grant on one of those external knowledge bases. A read grant is not enough, and an unrelated user cannot reach the route at all.
The damage scales with sharing. It is worst when one connection backs several knowledge bases, because deleting a single knowledge base destroys the connection for all of them.
Impact
An ordinary user removes instance-wide configuration that only administrators can create or manage. Every other external knowledge base bound to th…
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-2026-87998 has been found in open-webui.
Attackers can target a specific entry point like DELETE /api/v1/knowledge/{id}/delete. over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 7.1/10.
What to do: upgrade open-webui to 0.11.1 or later.
If unsure, ask your IT team or search "open-webui CVE-2026-87998" on the vendor's site.
CVE-2026-87998 (open-webui) — CWE-269 / CVSS v3 7.1
Attack vector: remote (network-reachable) / no user interaction
Attack surface: DELETE /api/v1/knowledge/{id}/delete. / DELETE /api/v1/knowledge/external/connections/{id} / DELETE /api/v1/knowledge/{KB_A}/delete
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.
A vulnerability (CWE-269) exists in open-webui. Attackers reach the vulnerable code path via DELETE /api/v1/knowledge/{id}/delete..
Check the vendor advisory for the affected versions of open-webui. Attack surface: DELETE /api/v1/knowledge/{id}/delete. / DELETE /api/v1/knowledge/external/connections/{id} / DELETE /api/v1/knowledge/{KB_A}/delete.
Severity: High (CVSS 7.1/10). Data can be tampered with by attackers.
Update to 0.11.1.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual DELETE /api/v1/knowledge/{id}/delete. 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 'DELETE /api/v1/knowledge/{id}/delete.' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
DELETE /api/v1/knowledge/{id}/delete.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 0.11.1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。
-
4Post-deployment verification verify
Replay attack against DELETE /api/v1/knowledge/{id}/delete. 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
- advisory github.com
- package github.com
- package pypi.org
- web github.com
- web github.com
- web github.com
- web github.com