Stored Cross-site Scripting (XSS) vulnerability in Outline editor
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-79.
Summary
Outline is an open source, collaborative document editor. A type confusion issue was found in ProseMirror’s rendering process that leads to a Stored Cross-Site Scripting (XSS) vulnerability in Outline. An authenticated user can create a document containing a malicious JavaScript payload. When other users view this document, the malicious Javascript can execute in the origin of Outline. Outline includes CSP rules to prevent third-party code execution, however in the case of self-hosting and having your file storage on the same domain as Outline a malicious payload can be uploaded as a file attachment and bypass those CSP restrictions. This issue has been addressed in release version 0.77.3. Users are advised to upgrade. There are no known workarounds for this vulnerability.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA outline (outline) Fixed in 0.77.3
Timeline
- 2026-10-02 Threatist record created from CVE-2024-40626
References
More Outline vulnerabilities
- TI-2026-26021 Outline has a rate limit bypass that allows brute force of email login OTP CVSS 4.0CRITICAL 9.1
- TI-2026-20086 Outline's IDOR allows unauthorized viewing and seizing of private deleted drafts CVSS 3.1HIGH 8.8
- TI-2024-25167 An issue in Outline <= v0.76.1 allows attackers to execute a session hijacking attack via… CVSS 3.1HIGH 8.8
- TI-2026-30168 Outline has IDOR in document share creation that allows unauthorized access to private documents across workspaces CVSS 3.1HIGH 7.7
- TI-2026-32586 Outline: Slack OAuth state can link a victim Outline account to an attacker Slack identity CVSS 3.1MEDIUM 6.5
- TI-2024-25168 An issue in Outline <= v0.76.1 allows attackers to redirect a victim user to a malicious… CVSS 3.1MEDIUM 6.1
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences