Vulnerability in open-webui (CVE-2026-87994)
Summary
Vulnerability in open-webui (CVE-2026-87994). Risk of unauthorized operations or information disclosure. Exploitable via POST /api/v1/channels/. Mitigation: upgrade to 0.11.1 or later.
Original description
The description as published by the source.
Summary
Any member of a channel who can post to it could also replace the text of a message written by a different member. The channel branch of the chat completions endpoint checked that the caller may write to the channel, and that the targeted message belongs to that channel, but never checked that the caller actually wrote the message being edited. The message kept its original author, so the replacement text was displayed and stored as though the victim had written it. The dedicated channel message edit route performed the authorship check correctly and refused the same edit, so the two paths disagreed about who may modify a message.
Preconditions
- Channels must be enabled.
ENABLE_CHANNELSdefaults toFalse, so a default deployment is not affected until an administrator turns channels on. - The attacker must be an approved user holding write access to the target channel, which is the ordinary state for any participant. No elevated role, group membership or additional permission is needed, and the attacker does not need to be the channel owner.
- The attacker must know the id of the targeted message. That id is returned to every member who reads the channel, so it requires no further access.
- Channels the attacker cannot post to are not affected, and neither are deployments with channels disabled.
Impact
An attacker can rewrite what another member said, under that member's name, in a shared channel. The stored record and every later reader show the victim…
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-2026-87994 has been found in open-webui.
Attackers can target a specific entry point like POST /api/v1/channels/ 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 0.11.1 or later.
If unsure, ask your IT team or search "open-webui CVE-2026-87994" on the vendor's site.
CVE-2026-87994 (open-webui) — CWE-639 / CVSS v3 4.3
Attack vector: remote (network-reachable) / no user interaction
Attack surface: POST /api/v1/channels/ / POST /api/chat/completions / ENABLE_CHANNELS / False
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-639) exists in open-webui. Attackers reach the vulnerable code path via POST /api/v1/channels/.
Check the vendor advisory for the affected versions of open-webui. Attack surface: POST /api/v1/channels/ / POST /api/chat/completions / ENABLE_CHANNELS / False.
Severity: Medium (CVSS 4.3/10). Risk of unauthorized operations or information disclosure.
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 POST /api/v1/channels/ 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/channels/' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /api/v1/channels/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 POST /api/v1/channels/ 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