In short
- CVE-2026-104846 is a CRITICAL (CVSS 9.8) vulnerability affecting seroval.
- Chance of exploitation in the next 30 days (EPSS): 0.34%, higher than 28.1% of all vulnerabilities.
- Fix: update to 1.6.2 or later.
| Package | Affected versions | Patched versions |
|---|
| seroval npm | ≥ 0.12.0, < 1.6.2
| 1.6.2
|
Description
A fulfilled Promise node deserialized by fromJSON() can trigger unintended invocation of a plugin-produced callable through native ECMAScript thenable assimilation. This bypasses the type-confusion fix in [email protected] (GHSA-mv8w-475r-vwqw / CVE-2026-59940) and affects every plugin-capable release from 0.12.0 through the current 1.6.0.
NVD description
Seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities. From 0.12.0 until 1.6.2, fromJSON deserialization of a fulfilled Promise control node can pass a plugin-produced callable-bearing thenable to a native Promise resolver. ECMAScript thenable assimilation then invokes the callable unexpectedly, allowing attacker-controlled JSON to trigger code in applications using plugin-capable Seroval releases. This path bypasses the Promise resolver type-confusion remediation in version 1.5.3 for CVE-2026-59940 because the unexpected invocation occurs through native Promise settlement after the referenced value is deserialized. This issue is fixed in version 1.6.2.
Running one of these products? Scan your site to see whether it exposes a vulnerable version.
Scan my site free