CVE-2022-39239

@netlify/ipx vulnerable to Full Response SSRF and Stored XSS via Cache Poisoning and Improper Host Validation

Workarounds

The problem is no longer exploitable on Netlify as the CDN now sanitizes the relevant header. Cached content can be cleared by re-deploying the site.

By sending specially crafted headers an attacker can bypass the source image domain allowlist, causing the handler to load and return arbitrary images. Because the response is cached globally, this image will then be served to visitors without requiring those headers to be set. XSS can be achieved by requesting a malicious SVG with embedded scripts, which would then be served from the site domain. Note that this does not apply to images loaded in <img> tags, as scripts do not execute in this context. The image URL can be set in the header independently of the request URL, meaning any site images that have not previously been cached can have their cache poisoned.

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.

CVE-2022-39239 has a CVSS score of 6.1 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.2.3); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

This problem has been fixed in version 1.2.3

1. What is CVE-2022-39239? CVE-2022-39239 is a medium-severity cross-site scripting (XSS) vulnerability in @netlify/ipx (npm), affecting versions < 1.2.3. It is fixed in 1.2.3. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
2. How severe is CVE-2022-39239? CVE-2022-39239 has a CVSS score of 6.1 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of @netlify/ipx are affected by CVE-2022-39239? @netlify/ipx (npm) versions < 1.2.3 is affected.
4. Is there a fix for CVE-2022-39239? Yes. CVE-2022-39239 is fixed in 1.2.3. Upgrade to this version or later.
5. Is CVE-2022-39239 exploitable, and should I be worried? Whether CVE-2022-39239 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
6. What actually determines whether CVE-2022-39239 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.
7. How do I fix CVE-2022-39239? Upgrade @netlify/ipx to 1.2.3 or later.