Cross-Site Request Forgery (CSRF) in Outline (CVE-2026-44695)
Summary
Vulnerability in Outline (CVE-2026-44695). Confidential information can be exposed externally. Exploitable via GET /auth/slack.post. Mitigation: upgrade to 1.7.1 or later.
Original description
The description as published by the source.
Outline is a service that allows for collaborative documentation. Prior to 1.7.1, the Slack integration callback for GET /auth/slack.post accepts an unsigned, session-independent OAuth state value. A third party who can obtain a Slack OAuth code for the same Outline Slack client can make a logged-in Outline user complete the callback and link that user's Outline account to the attacker's Slack team_id and user_id. The linked Slack identity can then use the Slack /outline search command as the victim Outline user. This vulnerability is fixed in 1.7.1.
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-2026-44695 has been found in Outline.
Attackers can target a specific entry point like GET /auth/slack.post over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 5.8/10.
What to do: upgrade Outline to 1.7.1 or later.
If unsure, ask your IT team or search "Outline CVE-2026-44695" on the vendor's site.
CVE-2026-44695 (Outline) — CWE-352 / CVSS v3 5.8
Attack vector: remote (network-reachable)
Attack surface: GET /auth/slack.post
Patched: 1.7.1 — 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.
CSRF (CWE-352) exists in Outline. Attackers reach the vulnerable code path via GET /auth/slack.post.
Check the vendor advisory for the affected versions of Outline. Attack surface: GET /auth/slack.post.
Severity: Medium (CVSS 5.8/10). Confidential information can be exposed externally.
Update to 1.7.1.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual GET /auth/slack.post requests with malformed payloads or SQL meta-characters. Run grep -r 'Outline' . 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 'Outline' . | 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
Outline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 /auth/slack.post' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
GET /auth/slack.post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 Outline to 1.7.1ステージング環境で 1.7.1 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 GET /auth/slack.post 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。
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov