Vulnerability in open-webui (CVE-2026-28786)
Summary
Vulnerability in open-webui (CVE-2026-28786). Risk of unauthorized operations or information disclosure. Exploitable via FileNotFoundError. Mitigation: upgrade to 0.8.6 or later.
Original description
The description as published by the source.
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to version 0.8.6, an unsanitized filename field in the speech-to-text transcription endpoint allows any authenticated non-admin user to trigger a FileNotFoundError whose message — including the server's absolute DATA_DIR path — is returned verbatim in the HTTP 400 response body, confirming information disclosure on all default deployments. Version 0.8.6 patches the issue.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
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-2026-28786 has been found in open-webui.
Attackers can target a specific entry point like FileNotFoundError over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade open-webui to 0.8.6 or later.
If unsure, ask your IT team or search "open-webui CVE-2026-28786" on the vendor's site.
CVE-2026-28786 (open-webui) — CWE-209
Attack vector: remote (network-reachable) / no user interaction
Attack surface: FileNotFoundError / DATA_DIR / filename / except
Patched: 0.8.6 — 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-209) exists in open-webui. Attackers reach the vulnerable code path via FileNotFoundError.
Check the vendor advisory for the affected versions of open-webui. Attack surface: FileNotFoundError / DATA_DIR / filename / except.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 0.8.6.
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
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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 0.8.6ステージング環境で 0.8.6 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
- advisory github.com
- package github.com
- web github.com