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.
Conclusion & alert: CVE-2024-40626 is rated Exploit Available (57.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.17%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
| EDB-ID | Source | Kind | Published | Link |
|---|---|---|---|---|
| — | nvd_ref | exploit_tag | Exploit-DB ↗ |
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2025-12-05 | 0.12% | 0.17% | +0.05% |
| 2 | 2025-11-21 | 1.05% | 0.12% | -0.93% |
| 3 | 2025-11-18 | — | 1.05% | — |
Full EPSS history (12 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.3 | 3.1 | HIGH |
|
2.1 | 5.2 | [email protected] |
| 5.4 | 3.1 | MEDIUM |
|
2.3 | 2.7 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| getoutline | outline | < 0.77.3 | cpe:2.3:a:getoutline:outline:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://github.com/outline/outline/security/advisories/GHSA-888c-mvg8-v6wh | Exploit Vendor Advisory |