Authorization Flaw in open-webui (CVE-2026-45316)
Summary
Vulnerability in open-webui (CVE-2026-45316). Risk of unauthorized operations or information disclosure. Exploitable via POST /api/v1/notes/{id}/pin. Mitigation: upgrade to 0.9.3 or later.
Original description
The description as published by the source.
Summary
The POST /api/v1/notes/{id}/pin endpoint performs a write operation (toggling the is_pinned field) but only checks for read permission. Users with read-only access to a shared note can pin/unpin it, which is a state-modifying action that should require write permission. All other write endpoints (update, delete, access/update) correctly check for write permission.
Details
Affected code: backend/open_webui/routers/notes.py lines 412-444
@router.post('/{id}/pin', response_model=Optional[NoteModel])
async def pin_note_by_id(...):
# ...
if user.role != 'admin' and (
user.id != note.user_id
and not await AccessGrants.has_access(
user_id=user.id,
resource_type='note',
resource_id=note.id,
permission='read', # BUG: should be 'write'
db=db,
)
):
raise HTTPException(...)
note = await Notes.toggle_note_pinned_by_id(id, db=db) # write operation
Compare with update endpoint (correct, line 318-327):
async def update_note_by_id(...):
# ...
and not await AccessGrants.has_access(
permission='write', # correctly checks 'write'
)
PoC
Environment: Open WebUI v0.9.2, default configuration with notes sharing enabled.
Setup:
- UserA creates a note
- UserA shares note with UserB with
readpermission viaPOST /api/v1/notes/{id}/access/updatewith `{"access_grants":[…
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-2026-45316 has been found in open-webui.
Attackers can target a specific entry point like POST /api/v1/notes/{id}/pin over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 3.5/10.
What to do: upgrade open-webui to 0.9.3 or later.
If unsure, ask your IT team or search "open-webui CVE-2026-45316" on the vendor's site.
CVE-2026-45316 (open-webui) — CWE-863 / CVSS v3 3.5
Attack vector: remote (network-reachable)
Attack surface: POST /api/v1/notes/{id}/pin / POST /api/v1/notes/{id}/access/update / is_pinned / read
Patched: 0.9.3 — 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.
Incorrect authorization (CWE-863) exists in open-webui. Attackers reach the vulnerable code path via POST /api/v1/notes/{id}/pin.
Check the vendor advisory for the affected versions of open-webui. Attack surface: POST /api/v1/notes/{id}/pin / POST /api/v1/notes/{id}/access/update / is_pinned / read.
Severity: Low (CVSS 3.5/10). Risk of unauthorized operations or information disclosure.
Update to 0.9.3.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual POST /api/v1/notes/{id}/pin 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 'POST /api/v1/notes/{id}/pin' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /api/v1/notes/{id}/pin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 0.9.3ステージング環境で 0.9.3 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 POST /api/v1/notes/{id}/pin 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
- web github.com