NPM · JULY 2026 · EARLY WARNING

seroval npm Package Type Confusion Issue: Early Warning

EARLY WARNING · UNCONFIRMED. This page describes a developing threat that 0Day surfaced from early signals and has not yet independently confirmed. Details may change. Always verify against the primary sources before acting.
GHSA-MV8W-475R-VWQWSeverity: HIGH

An early warning has been issued regarding a type confusion issue in the seroval npm package versions prior to 1.5.3, which could potentially allow attacker-controlled deserialization side effects.

What happened

Reportedly, a type confusion issue in the `seroval.fromJSON()` function allows attacker-controlled JSON input to cause Promise control nodes to operate on values from the general deserialization reference table without verifying that those values are genuine internal promise resolver records. This could potentially allow attacker-controlled deserialization side effects.

The issue is under investigation and has been tracked with the ID GHSA-MV8W-475R-VWQW. The recommended action for those affected is to upgrade to `seroval@1.5.3` or later.

For more detailed information, primary sources should be consulted. The severity of this issue is currently classified as high.

How 0Day mitigates this

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