Conform: parseSubmission vulnerable to CPU exhaustion when parsing many unique form fields (CVE-2026-49250) | HOL Guard CVE

High severityCVE-2026-49250GHSA-525M-7F82-2MF7

Conform: parseSubmission vulnerable to CPU exhaustion when parsing many unique form fields

Answer in brief

CVE-2026-49250 records a High severity vulnerability in Conform: parseSubmission vulnerable to CPU exhaustion when parsing many unique form fields. The current sources do not mark it as known exploited. The current feed maps edmundhung/conform (generic), @conform-to/dom (npm). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 14, 2026Updated Sep 14, 2026Source checked Sep 14, 2026First seen by HOL Jul 2, 2026Material review Sep 14, 2026

Upstream Advisory

Key facts

Risk: High
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps edmundhung/conform (generic), @conform-to/dom (npm). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
edmundhung/conformgeneric	>= 1.8.0, < 1.19.4	Not reported
@conform-to/domnpm	>=1.8.0,<1.19.4	1.19.4

Recommended response

Check inventory. Check lockfiles and deployed manifests for edmundhung/conform, @conform-to/dom.
Review the reported fix. Update @conform-to/dom to 1.19.4 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 14, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 14, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jul 2, 2026

Sources and claim methodology

Upstream source description

Conform, a type-safe form validation library, allows the parsing of nested objects in the form of object.property. From 1.8.0 until 1.19.4, the parseSubmission future API in packages/conform-dom/formdata.ts repeatedly scans FormData or URLSearchParams entries by each unique field name. An unauthenticated attacker can submit a crafted form containing many unique names, causing excessive synchronous CPU work and denial of service in an application that passes the submission to parseSubmission. Applications should continue to enforce request parsing limits before invoking Conform. This issue is fixed in version 1.19.4.

Quoted source text, attributed separately from HOL analysis.