Vulnerability in open-webui (CVE-2026-44559)
Summary
Vulnerability in open-webui (CVE-2026-44559). Risk of unauthorized operations or information disclosure. Exploitable via GET /api/v1/channels/{id}/members. Mitigation: upgrade to 0.9.0 or later.
Original description
The description as published by the source.
Missing Access Check on Channel Members Endpoint for Standard Channels
Affected Component
Channel members listing endpoint:
backend/open_webui/routers/channels.py(lines 445-507,get_channel_members_by_id)
Affected Versions
Current main branch and likely all versions with the channels feature.
Description
The GET /api/v1/channels/{id}/members endpoint only checks membership for group and dm channel types (lines 467-469). For standard channels — including private ones — there is no channel_has_access check before returning the member list. Any authenticated user who knows a private channel's UUID can enumerate all users with access to that channel.
# Line 467-469: only group/dm channels are checked
if channel.type in ['group', 'dm']:
if not Channels.is_user_channel_member(channel.id, user.id, db=db):
raise HTTPException(...)
# Standard channels fall through with NO access check
Compare with other channel endpoints (e.g., get_channel_messages at line 688) which correctly call channel_has_access(user.id, channel, permission='read') for standard channels.
CVSS 3.1 Breakdown
| Metric | Value | Rationale |
|---|---|---|
| Attack Vector | Network (N) | Exploited remotely via API call |
| Attack Complexity | Low (L) | Single API call, no special conditions |
| Privileges Required | Low (L) | Requires a valid user account |
| User Interaction | None (N) | No victim interaction required |
| Scope | Unc… |
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-2026-44559 has been found in open-webui.
Attackers can target a specific entry point like GET /api/v1/channels/{id}/members over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 4.3/10.
What to do: upgrade open-webui to 0.9.0 or later.
If unsure, ask your IT team or search "open-webui CVE-2026-44559" on the vendor's site.
CVE-2026-44559 (open-webui) — CWE-862 / CVSS v3 4.3
Attack vector: remote (network-reachable) / no user interaction
Attack surface: GET /api/v1/channels/{id}/members / get_channel_members_by_id / group / channel_has_access
Patched: 0.9.0 — 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 GET /api/v1/channels/{id}/members.
Check the vendor advisory for the affected versions of open-webui. Attack surface: GET /api/v1/channels/{id}/members / get_channel_members_by_id / group / channel_has_access.
Severity: Medium (CVSS 4.3/10). Risk of unauthorized operations or information disclosure.
Update to 0.9.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual GET /api/v1/channels/{id}/members 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 'GET /api/v1/channels/{id}/members' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
GET /api/v1/channels/{id}/members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 0.9.0ステージング環境で 0.9.0 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 GET /api/v1/channels/{id}/members 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
- package github.com
- web github.com
- web github.com