CVE-2023-40013: SVG Loader is a javascript library that fetches SVGs using XMLHttpRequests and injects the SVG code in the tag's place. According to the docs, svg-loa...

Description

SVG Loader is a javascript library that fetches SVGs using XMLHttpRequests and injects the SVG code in the tag's place. According to the docs, svg-loader will strip all JS code before injecting the SVG file for security reasons but the input sanitization logic is not sufficient and can be trivially bypassed. This allows an attacker to craft a malicious SVG which can result in Cross-site Scripting (XSS). When trying to sanitize the svg the lib removes event attributes such as `onmouseover`, `onclick` but the list of events is not exhaustive. Any website which uses external-svg-loader and allows its users to provide svg src, upload svg files would be susceptible to stored XSS attack. This issue has been addressed in commit `d3562fc08` which is included in releases from 1.6.9. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Metrics

CVSS 3.1

5.4/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

0.47%

37.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Shubhamjain	Svg Loader	< 1.6.9

References

Timeline

Published: Aug 14, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-40013?

SVG Loader is a javascript library that fetches SVGs using XMLHttpRequests and injects the SVG code in the tag's place. According to the docs, svg-loader will strip all JS code before injecting the SVG file for security reasons but the input sanitization logic is not sufficient and can be trivially bypassed. This allows an attacker to craft a malicious SVG which can result in Cross-site Scripting (XSS). When trying to sanitize the svg the lib removes event attributes such as `onmouseover`, `onclick` but the list of events is not exhaustive. Any website which uses external-svg-loader and allows its users to provide svg src, upload svg files would be susceptible to stored XSS attack. This issue has been addressed in commit `d3562fc08` which is included in releases from 1.6.9. Users are advised to upgrade. There are no known workarounds for this vulnerability.

How severe is CVE-2023-40013?

CVE-2023-40013 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 0.47% probability of exploitation in the next 30 days.

How do I fix CVE-2023-40013?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.