PT-2026-42683 · Umbraco · Umbraco Cms

Published 2026-05-21 · Updated 2026-05-21 · CVE-2026-46609

Positive Technologies (AI Summary)

CVSS v3.1

4.6

Medium

Base vector

AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

Name of the Vulnerable Software and Affected Versions Umbraco CMS versions prior to 17.4.0

Description Authenticated users can inject HTML into an input field. This content is then rendered in the confirmation dialog without proper output encoding, leading to Cross-Site Scripting (XSS) or HTML injection. Output encoding is the process of converting special characters into a safe form to prevent the browser from interpreting them as active code.

Recommendations Update to version 17.4.0.

Fix

XSS

Weakness Enumeration

CWE-79

Related Identifiers

CVE-2026-46609

GHSA-VR9V-27GG-QGX4

Affected Products

Umbraco Cms

References · 4

• https://osv.dev/vulnerability/GHSA-vr9v-27gg-qgx4 · Vendor Advisory
• https://github.com/umbraco/Umbraco-CMS/security/advisories/GHSA-vr9v-27gg-qgx4 · Note
• https://github.com/umbraco/Umbraco-CMS · Note
• https://twitter.com/dailycve/status/2057610866791489998 · Twitter Post