CVE-2026-49250: @conform to/dom @conform-to/dom ParseSubmission Vulnerable To CPU Vulnerability

HIGH
Advisory Identifier: GHSA-525m-7f82-2mf7
Share
CWE-407
Published
Advisory Summary

CVE-2026-49250 is a HIGH @conform-to/dom parsesubmission vulnerable to cpu vulnerability (CWE-407: Inefficient Algorithmic Complexity) affecting @conform to/dom libraries in the npm ecosystem. The issue involves @conform-to/dom parsesubmission vulnerable to cpu exhaustion when parsing many unique form fields. Remediation is available by upgrading affected packages to version 1.19.4.

CVE-2026-49250 at a Glance

CVE Identifier CVE-2026-49250
GHSA Identifier GHSA-525m-7f82-2mf7
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-407: Inefficient Algorithmic Complexity
Affected Product @conform to/dom
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2026-49250

To remediate this vulnerability, upgrade all affected @conform to/dom dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

@conform-to/dom fixed: 1.19.4 
npm install @conform-to/dom@1.19.4
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls @conform-to/dom

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-49250, inspect your project dependencies using npm:

npm ls @conform-to/dom

Analyze the terminal output to locate any version of @conform to/dom in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.19.4), your application is affected.

Note: The npm ls @conform-to/dom command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-407: Inefficient Algorithmic Complexity, where an algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached. In @conform to/dom, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

A CPU exhaustion vulnerability exists in Conform's [`parseSubmission`](https://conform.guide/api/react/future/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](https://www.npmjs.com/package/@remix-run/form-data-parser) provides `maxParts`, `maxTotalSize`, `maxFileSize`, `maxFiles`, and `maxHeaderSize` options.

CVE-2026-49250 Affected @conform to/dom Versions

1 component(s)
Fixed Versions:
1.19.4
Product / Package Ecosystem Affected Versions Fixed Version
@conform-to/dom
npm/@conform-to/dom
npm
≥ 1.8.0
< 1.19.4
1.19.4

References

GitHub Advisory / Wiki ADVISORY
https://github.com/edmundhung/conform/security/advisories/GHSA-525m-7f82-2mf7
@conform to/dom Source Repository REPOSITORY
https://github.com/edmundhung/conform

Frequently Asked Questions

What is CVE-2026-49250?
CVE-2026-49250 is a security vulnerability in @conform to/dom involving @conform-to/dom parseSubmission vulnerable to CPU exhaustion when parsing many unique form fields under CWE-407: Inefficient Algorithmic Complexity.
Which @conform to/dom versions are affected?
Affected versions include releases prior to 1.19.4 across affected packages: @conform-to/dom.
What version fixes CVE-2026-49250?
Upgrading to 1.19.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is @conform-to/dom affected?
Yes, @conform-to/dom is affected in releases prior to 1.19.4. Upgrade your dependency to 1.19.4 or later.
What CWE is associated with CVE-2026-49250?
CVE-2026-49250 is classified under CWE-407: Inefficient Algorithmic Complexity (An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.).
How can I check npm dependencies for CVE-2026-49250?
Run the dependency tree command: 'npm ls @conform-to/dom'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-525m-7f82-2mf7",
  "modified" : "2026-07-02T19:18:41Z",
  "published" : "2026-07-02T19:18:41Z",
  "aliases" : [ "CVE-2026-49250" ],
  "summary" : "@conform-to/dom parseSubmission vulnerable to CPU exhaustion when parsing many unique form fields",
  "details" : "A CPU exhaustion vulnerability exists in Conform's [`parseSubmission`](https://conform.guide/api/react/future/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.\n\n> [!NOTE]\n> 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](https://www.npmjs.com/package/@remix-run/form-data-parser) provides `maxParts`, `maxTotalSize`, `maxFileSize`, `maxFiles`, and `maxHeaderSize` options.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@conform-to/dom"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.8.0"
      }, {
        "fixed" : "1.19.4"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/edmundhung/conform/security/advisories/GHSA-525m-7f82-2mf7"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/edmundhung/conform"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-407" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-02T19:18:41Z",
    "nvd_published_at" : null
  }
}