CVE-2026-43887

Outline: Stored XSS via Comment Mentions

State: Published
Severity: 7.3 High
Published: May 11, 2026
Updated: May 15, 2026
Reserved: May 4, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
3.1	7.3 High	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N	GitHub_M

Weaknesses

CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Affected Products

Product	Versions
outlineoutline	>= 0.84.0, < 1.7.0Affected

References

https://github.com/outline/outline/security/advisories/GHSA-rqrg-f3qc-xvgh

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