Seroval: Code injection through a typed array's own constructor property

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

5.3 · 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 · score source

EPSS

• CVE-2026-116583: 0.27% estimated exploitation activity in the next 30 days; percentile 19.00 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary seroval writes a typed array as a call to its constructor. In affected versions, the constructor name in the output is read from a property that data on the value can replace, and it is written without checks. A typed array that received properties from untrusted data can then put arbitrary code into the serialized output.

Details Version 1.6.0 changed how seroval finds the class of an object, so that objects with their own `constructor` property serialize correctly. Typed arrays still took the constructor name from the value itself, so the name could come from the untrusted property instead of the array's real type. These functions are affected: - `serialize`, `serializeAsync` - `crossSerialize`, `crossSerializeAsync`, `crossSerializeStream` - the `Serializer` class - `compileJSON` `fromJSON` and `fromCrossJSON` are not affected: they only accept the names of the built-in typed arrays. With the `compactArrayBufferViews` option, the same lookup throws a `TypeError`…

Published by the source

28 Oct 2026, 21:17 UTC

Last modified by the source

28 Oct 2026, 21:30 UTC

Source last checked

29 Oct 2026, 06:00 UTC

1. Revision 2 · amended · 29 Oct 2026

   Amended from osv record GHSA-f86p-h4j2-7qgj

2. Revision 1 · created · 28 Oct 2026

   Published from ghsa record GHSA-f86p-h4j2-7qgj

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# Patch Next advisory brief: CVE-2026-116583

Advisory: Seroval: Code injection through a typed array's own constructor property
IDs: CVE-2026-116583, GHSA-f86p-h4j2-7qgj
Record: https://patchnext.com/advisories/cve-2026-116583 (revision 2, source checked 29 Oct 2026, 06:00 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: seroval 1.6.11. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm seroval: affected >= 1.6.0, < 1.6.11; fixed in 1.6.11

## Suggested inspection (read-only)
- `npm ls seroval --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on seroval.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-f86p-h4j2-7qgj (OSV record GHSA-f86p-h4j2-7qgj lists affected ranges: npm seroval >=1.6.0 <1.6.11 (fixed))
- Verified: https://github.com/advisories/GHSA-f86p-h4j2-7qgj (GitHub-reviewed advisory GHSA-f86p-h4j2-7qgj lists affected ranges: npm seroval >=1.6.0 <1.6.11)

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