CVE-2026-43887
Outline: Stored XSS via Comment Mentions
CVSS Score
7.3
EPSS Score
0.0%
EPSS Percentile
0th
Outline is a service that allows for collaborative documentation. From 0.84.0 to 1.6.1, the Outline comment section permits users to mention other users; however, the backend does not validate or sanitize the href attribute associated with these mentions. As a result, potentially dangerous protocols (e.g., javascript:) are not filtered, introducing a risk of client-side code execution. This vulnerability is fixed in 1.7.0.
| CWE | CWE-79 |
| Vendor | outline |
| Product | outline |
| Published | May 11, 2026 |
Stay Ahead of the Next One
Get instant alerts for outline outline
Be the first to know when new high vulnerabilities affecting outline outline are published — delivered to Slack, Telegram or Discord.
Get Free Alerts →
Free · No credit card · 60 sec setup
CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
Affected Versions
outline / outline
>= 0.84.0, < 1.7.0