CVE-2026-49250

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

Published Sep 14, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-525m-7f82-2mf7 @conform-to/dom parseSubmission vulnerable to CPU exhaustion when parsing many unique form fields
History
Type Values Removed Values Added
First Time appeared Edmundhung
Edmundhung conform
Vendors & Products Edmundhung
Edmundhung conform
Type Values Removed Values Added
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.
Title Conform: parseSubmission vulnerable to CPU exhaustion when parsing many unique form fields
Weaknesses CWE-407
References
Metrics cvssV4_0

{'score': 8.7, 'vector': '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'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 14, 2026, 7:01 PM
Reserved
May 28, 2026, 2:33 PM
Status
Deferred
Published
Sep 14, 2026, 6:17 PM
Modified
Sep 30, 2026, 7:57 PM