Summary
@conform-to/dom parseSubmission vulnerable to CPU exhaustion when parsing many unique form fields
A CPU exhaustion vulnerability exists in Conform's parseSubmission future API when parsing FormData or URLSearchParams submissions with many unique field names. The parser previously looked up values by field name, which could require repeated scans of the submitted entries and cause excessive synchronous CPU work if an attacker supplies a crafted submission.
[!NOTE]
The patched version fixes this by iterating submitted entries directly instead of repeatedly looking up values by field name. Applications that accept untrusted form submissions should still enforce request parsing limits before passing data to Conform. For multipart requests, @remix-run/form-data-parser provides maxParts, maxTotalSize, maxFileSize, maxFiles, and maxHeaderSize options.
Impact
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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Frequently Asked Questions
- What is CVE-2026-49250? CVE-2026-49250 is a high-severity security vulnerability in @conform-to/dom (npm), affecting versions >= 1.8.0, < 1.19.4. It is fixed in 1.19.4.
- Which versions of @conform-to/dom are affected by CVE-2026-49250? @conform-to/dom (npm) versions >= 1.8.0, < 1.19.4 is affected.
- Is there a fix for CVE-2026-49250? Yes. CVE-2026-49250 is fixed in 1.19.4. Upgrade to this version or later.
- Is CVE-2026-49250 exploitable, and should I be worried? Whether CVE-2026-49250 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 CVE-2026-49250 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 CVE-2026-49250? Upgrade
@conform-to/domto 1.19.4 or later.