# CVE-2026-116581: Seroval improper sequence node validation in deserialization

Source: https://junglewise.ai/threats/cve-2026-116581-seroval-facilitates-javascript-value-stringification-including  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-26. Updated: 2026-10-26  
License: CC BY 4.0 with a link back

CVE-2026-116581 · Severity: high · CVSS 7.5 · Published 2026-10-26

Seroval is a JavaScript library that serializes complex data structures for transport. A flaw in deserialization allows an attacker to send a specially crafted message that creates an infinite iterator; when an application consumes this iterator, it blocks the event loop and exhausts memory, causing denial of service. An unauthenticated attacker can trigger this by sending untrusted input to any service using vulnerable versions of Seroval.

Technologies: [Lxsmnsyc Seroval](https://junglewise.ai/threats/technologies/lxsmnsyc-seroval), [seroval (npm)](https://junglewise.ai/threats/technologies/seroval). Vendors: [Lxsmnsyc](https://junglewise.ai/threats/vendors/lxsmnsyc), [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-116581 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-116581 being exploited in the wild.

**How severe is CVE-2026-116581?** High severity, with a CVSS score of 7.5, published 26 October 2026.

**Which products and versions are affected?** Lxsmnsyc Seroval before 1.6.8; seroval (npm) <= 1.6.7, SEMVER:introduced=0,fixed=1.6.8.

**Is there a fix for CVE-2026-116581?** Yes. seroval (npm): upgrade to 1.6.8 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-116581 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-116581?** Check whether you run Lxsmnsyc Seroval or seroval (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- seroval (npm): upgrade to 1.6.8 or later

  ```sh
  npm install seroval@1.6.8
  ```


## Technical details

The vulnerability exists in the fromJSON and fromCrossJSON deserialization functions prior to version 1.6.8, which fail to validate a sequence node's done index during deserialization. An attacker can craft a sequence with a malicious done index that produces an iterator object that never completes iteration. This leads to an infinite loop when application code consumes the iterator, blocking the event loop and exhausting process memory. The fix validates sequence indices during deserialization to prevent this condition.

## Affected products

- lxsmnsyc Seroval before 1.6.8

## Identifiers

- CVE-2026-116581
- GHSA-97r2-qh9m-474h

## Timeline

- 2026-10-26: disclosed
- 2026-09-29: patched: Version 1.6.8 released

## References

- [https://github.com/lxsmnsyc/seroval/commit/e176f9267e59ddd6c9de89cc9fe85c5b37a5b728](https://github.com/lxsmnsyc/seroval/commit/e176f9267e59ddd6c9de89cc9fe85c5b37a5b728)
- [https://github.com/lxsmnsyc/seroval/releases/tag/seroval@1.6.8](https://github.com/lxsmnsyc/seroval/releases/tag/seroval@1.6.8)

## Related threats

- [Seroval denial of service via array-like object in deserialization](https://junglewise.ai/threats/cve-2026-116584-seroval-facilitates-javascript-value-stringification-including)
- [Seroval typed array constructor name injection](https://junglewise.ai/threats/cve-2026-116583-seroval-facilitates-javascript-value-stringification-including)
- [Seroval JavaScript RegExp code injection in HTML script elements](https://junglewise.ai/threats/cve-2026-116582-seroval-facilitates-javascript-value-stringification-including)
- [Seroval incomplete fix for AsyncIterator deserialization bypass](https://junglewise.ai/threats/cve-2026-116580-seroval-facilitates-javascript-value-stringification-including)
- [Seroval Promise thenable code execution via fromJSON deserialization](https://junglewise.ai/threats/cve-2026-104846-seroval-facilitates-js-value-stringification-including-complex)