Is CVE-2026-23957 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-23957 being exploited in the wild.

How severe is CVE-2026-23957?

Low severity, with a CVSS score of 3.1, published 21 January 2026.

Which products and versions are affected?

seroval (npm) SEMVER:introduced=0,fixed=1.4.1.

Is there a fix for CVE-2026-23957?

Yes. seroval (npm): upgrade to 1.4.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-23957 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-23957?

Check whether you run seroval (npm) 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-2026-23957: Seroval denial of service via array serialization

CVE-2026-23957 · Severity: low · CVSS 3.1 · Published 2026-01-21

Seroval is a JavaScript serialization library used to convert objects to and from a serialized format. An attacker can send maliciously crafted serialized data with excessively large array length values, causing the deserialization process to consume excessive CPU and time, leading to a denial of service that degrades application performance or availability.

Technologies: seroval (npm). Vendors: npm.

Quick answers

Is CVE-2026-23957 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-23957 being exploited in the wild.
How severe is CVE-2026-23957?: Low severity, with a CVSS score of 3.1, published 21 January 2026.
Which products and versions are affected?: seroval (npm) SEMVER:introduced=0,fixed=1.4.1.
Is there a fix for CVE-2026-23957?: Yes. seroval (npm): upgrade to 1.4.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-23957 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-23957?: Check whether you run seroval (npm) 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 1.4.1 or later
```
npm install seroval@1.4.1
```

Technical details

The vulnerability is a denial-of-service flaw rooted in inadequate input validation during array deserialization (CWE-770). The vulnerable code encodes array lengths in the serialized data without proper bounds checking. An attacker can override these length fields with extremely large values, forcing the deserialization routine to allocate memory and perform processing for an inflated array size, causing the application to hang or become unresponsive. The vulnerability requires no authentication and is reachable over the network if Seroval is used to deserialize untrusted input. The fix, available in version 1.4.1 and later, removes the explicit array length encoding and instead computes the length from Array.prototype.length during deserialization, eliminating the attack surface.

Affected products

<UNKNOWN> Seroval <=1.4.0

Identifiers

CVE-2026-23957
GHSA-66fc-rw6m-c2q6

Timeline

2026-01-21: disclosed
2026-01-21: patched: Version 1.4.1 released with fix

References

https://github.com/lxsmnsyc/seroval/security/advisories/GHSA-66fc-rw6m-c2q6

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