Is CVE-2026-104846 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-104846 being exploited in the wild.

How severe is CVE-2026-104846?

Critical severity, with a CVSS score of 9.8, published 2 October 2026.

Which products and versions are affected?

seroval (npm) >= 0.12.0, <= 1.6.0, SEMVER:introduced=0.12.0,fixed=1.6.2; Seroval 0.12.0 through 1.6.1.

Is there a fix for CVE-2026-104846?

Yes. seroval (npm): upgrade to 1.6.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-104846 attacked?

It is attacked over the network.

Am I affected by CVE-2026-104846?

Check whether you run seroval (npm) or Seroval 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.

CVE-2026-104846: Seroval Promise thenable code execution via fromJSON deserialization

Q: Is there a fix for CVE-2026-104846?

Yes. seroval (npm): upgrade to 1.6.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-104846 attacked?

It is attacked over the network.

Q: Am I affected by CVE-2026-104846?

Check whether you run seroval (npm) or Seroval 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.

CVE-2026-104846 · Severity: critical · CVSS 9.8 · Published 2026-10-02

Seroval is a JavaScript library that serializes and deserializes complex JavaScript objects beyond what standard JSON supports. A flaw in how it deserializes Promise objects allows an attacker to inject malicious code that executes when a crafted JSON payload is deserialized, potentially giving the attacker complete control over the application. Applications using Seroval's plugin system are vulnerable unless they upgrade.

Technologies: seroval (npm). Vendors: npm.

Quick answers

Is CVE-2026-104846 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-104846 being exploited in the wild.
How severe is CVE-2026-104846?: Critical severity, with a CVSS score of 9.8, published 2 October 2026.
Which products and versions are affected?: seroval (npm) >= 0.12.0, <= 1.6.0, SEMVER:introduced=0.12.0,fixed=1.6.2; Seroval 0.12.0 through 1.6.1.
Is there a fix for CVE-2026-104846?: Yes. seroval (npm): upgrade to 1.6.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-104846 attacked?: It is attacked over the network.
Am I affected by CVE-2026-104846?: Check whether you run seroval (npm) or Seroval 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 1.6.2 or later
```
npm install seroval@1.6.2
```

Technical details

The vulnerability exists in the fromJSON deserialization function when processing fulfilled Promise control nodes. A plugin-produced callable can be passed as a thenable to the native Promise resolver, triggering ECMAScript thenable assimilation which invokes the callable unexpectedly. This bypasses the type-confusion remediation from CVE-2026-59940 (v1.5.3) because the invocation occurs through native Promise settlement after value deserialization completes.

Affected products

Seroval Seroval 0.12.0 through 1.6.1

Identifiers

CVE-2026-104846
GHSA-p6vx-979v-rg4c

Timeline

2026-09-19: disclosed
2026-08-25: patched: Fix committed; version 1.6.2 released
2026-10-02: advisory

References

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