Summary
Sveltia CMS: Stored XSS in entry summary rendering via entity-decoded HTML
Workarounds
If upgrading is not immediately possible, avoid loading CMS content from untrusted authors and review content for entity-encoded HTML payloads in fields used by entry summaries.
Administrators can also reduce exposure by avoiding Markdown-enabled summary rendering for untrusted content where possible, or by ensuring repository write access is limited to trusted users only.
Resources
- CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- https://cwe.mitre.org/data/definitions/79.html
Impact
A stored cross-site scripting (XSS) vulnerability affected entry summary rendering in Sveltia CMS.
Entry summaries that allowed limited Markdown were parsed, sanitized, and then HTML entities were decoded. This order allowed specially crafted entity-encoded HTML, such as encoded tags or event handler attributes, to become active HTML after sanitization. When the resulting summary was rendered in the CMS UI, arbitrary JavaScript could execute in the browser of a user viewing the affected entry list or search result.
The practical impact is limited in currently supported Sveltia CMS usage because the CMS is intended for a single developer or a small trusted team, and open authoring / untrusted multi-user authoring is not currently implemented. Exploitation requires the ability to place malicious content into the repository or content source that the CMS loads.
Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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The issue has been patched by changing entry summary sanitization so that HTML entity decoding happens before sanitization for Markdown-enabled summaries. This ensures any decoded HTML is processed by the sanitizer before being rendered.
Users should upgrade to Sveltia CMS v0.160.1 or later.
Frequently Asked Questions
- What is GHSA-97R8-RF7Q-WMJW? GHSA-97R8-RF7Q-WMJW is a low-severity cross-site scripting (XSS) vulnerability in @sveltia/cms (npm), affecting versions < 0.160.0. It is fixed in 0.160.1. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- Which versions of @sveltia/cms are affected by GHSA-97R8-RF7Q-WMJW? @sveltia/cms (npm) versions < 0.160.0 is affected.
- Is there a fix for GHSA-97R8-RF7Q-WMJW? Yes. GHSA-97R8-RF7Q-WMJW is fixed in 0.160.1. Upgrade to this version or later.
- Is GHSA-97R8-RF7Q-WMJW exploitable, and should I be worried? Whether GHSA-97R8-RF7Q-WMJW is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-97R8-RF7Q-WMJW is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-97R8-RF7Q-WMJW? Upgrade
@sveltia/cmsto 0.160.1 or later.