CVE-2023-49279

Umbraco CMS vulnerable to stored XSS via SVG File Upload

MEDIUM

5.4

CVSS Score

Published: December 12, 2023 at 07:35 PM UTC

Updated: June 17, 2026 at 06:35 AM UTC

1 product affected across 1 vendorUmbraco-CMS

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Severity

MEDIUM5.4

Exploit prediction

EPSS 0.4%

SSVC

No known exploit

Description

Umbraco is an ASP.NET content management system (CMS). Starting in version 7.0.0 and prior to versions 7.15.11, 8.18.9, 10.7.0, 11.5.0, and 12.2.0, a user with access to the backoffice can upload SVG files that include scripts. If the user can trick another user to load the media directly in a browser, the scripts can be executed. Versions 7.15.11, 8.18.9, 10.7.0, 11.5.0, and 12.2.0 contain a patch for this issue. Some workarounds are available. Implement the server side file validation or serve all media from an different host (e.g cdn) than where Umbraco is hosted.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Umbraco-CMS · Umbraco

95%

v < 10.7.0v < 11.5.0v < 12.2.0v < 7.15.11v < 8.18.910.0.0 ≤ v < 10.7.011.0.0 ≤ v < 11.5.012.0.0 ≤ v < 12.2.07.0.0 ≤ v < 7.15.118.0.0 ≤ v < 8.18.9

Affected range stops below 10.7.0, so it looks safe — our inference, not a vendor statement

Affected range stops below 11.5.0, so it looks safe — our inference, not a vendor statement

Affected range stops below 12.2.0, so it looks safe — our inference, not a vendor statement

Affected range stops below 7.15.11, so it looks safe — our inference, not a vendor statement

Affected range stops below 8.18.9, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://github.com/umbraco/Umbraco-CMS/security/advisories/GHSA-6xmx-85x3-4cv2

References (2)

x_refsource_MISCProduct

Source: [email protected]

https://docs.umbraco.com/umbraco-cms/reference/security/serverside-file-validation

x_refsource_CONFIRMVendor Advisory

Source: [email protected]

https://github.com/umbraco/Umbraco-CMS/security/advisories/GHSA-6xmx-85x3-4cv2

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.4MEDIUM[email protected]

Attack Vector: NETWORK
Complexity: LOW
Privileges: LOW
User Interaction: REQUIRED
Scope: CHANGED
Confidentiality: LOW
Integrity: LOW
Availability: NONE

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-79

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