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CVE-2026-54020 medium CVSS 6.3

Vulnerability in open-webui (CVE-2026-54020)

Summary

Vulnerability in open-webui (CVE-2026-54020). Confidential information can be exposed externally. Exploitable via image_url. Mitigation: upgrade to 0.11.0 or later.

Original description

The description as published by the source.

Summary

Open WebUI vetted user-supplied URLs by resolving the hostname once and rejecting private, loopback and link-local addresses, then let the HTTP client resolve that hostname again at connect time. An attacker who controls the authoritative DNS for a hostname they submit can answer with a public address during the check and an internal one at connect, so the fetch reaches an address the check was meant to block. Every user-reachable fetch gated by that check was affected, and most of them hand the internal response back to the attacker.

Preconditions

  • An account on the instance. No admin rights and no non-default configuration.
  • Control of the authoritative DNS for a hostname the attacker submits, serving a TTL of 0 and alternating answers.
  • One of the affected entry points: URL ingest for retrieval, an image_url in a chat completion, image editing, or the OAuth profile-picture fetch.
  • The OAuth path additionally needs OAuth login configured and a picture claim (OAUTH_PICTURE_CLAIM, default picture) the user can influence, which is the case on self-service OIDC providers and providers with a user-editable avatar URL. On an existing account it also needs OAUTH_UPDATE_PICTURE_ON_LOGIN, which is off by default. Deployments without OAuth are not affected on that path; the other paths need no configuration at all.

Impact

The server can be made to issue requests to addresses only it can reach: cloud instance metadata such as 169.254.169.254, loopback-bo…

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-2026-54020 has been found in open-webui.
Attackers can target a specific entry point like image_url over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 6.3/10.
What to do: upgrade open-webui to 0.11.0 or later.
If unsure, ask your IT team or search "open-webui CVE-2026-54020" on the vendor's site.

CVE-2026-54020 (open-webui) — CWE-367 / CVSS v3 6.3
Attack vector: remote (network-reachable) / no user interaction
Attack surface: image_url / OAUTH_PICTURE_CLAIM / picture / OAUTH_UPDATE_PICTURE_ON_LOGIN
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.

❓ What is the problem

A vulnerability (CWE-367) exists in open-webui. Attackers reach the vulnerable code path via image_url.

📍 Affected scope

Check the vendor advisory for the affected versions of open-webui. Attack surface: image_url / OAUTH_PICTURE_CLAIM / picture / OAUTH_UPDATE_PICTURE_ON_LOGIN.

🔥 Severity

Severity: Medium (CVSS 6.3/10). Confidential information can be exposed externally.

🔧 How to fix

Update to 0.11.0.

🛡️ 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 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

  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
    Apply 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。

  3. 3
    Post-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

pip open-webui
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.11.0"}]}]
PyPI open-webui
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.11.0"}]}]

References

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