CVE-2026-46609 | Umbraco.Cms: XSS/HTML Injection in Umbraco Backoffice confirmation dialog

Umbraco is an ASP.NET CMS. From version 14.0.0 to before version 17.4.0, authenticated users are able to inject HTML into an input field, which is rendered in the confirmation dialog without proper output encoding. This issue has been patched in version 17.4.0.

Published: 2026-06-10 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-46609 is rated Low Risk (19.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.14%). Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-46609

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 2026-06-15 0.03% 0.14% +0.11%
2 2026-06-11 — 0.03% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-46609

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.6 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.1 2.5 [email protected]

Weakness enumeration for CVE-2026-46609

GitHub Security Advisory for CVE-2026-46609

GHSA-vr9v-27gg-qgx4 · Severity: medium · Ecosystem: nuget — Umbraco.Cms: XSS/HTML Injection in Umbraco Backoffice confirmation dialog

Affected software / configurations for CVE-2026-46609

Vendor Product Version Raw CPE
umbraco umbraco_cms >= 14.0.0, < 17.4.0 cpe:2.3:a:umbraco:umbraco_cms:*:*:*:*:*:*:*:*

References for CVE-2026-46609

cvelogic Threat Intelligence