# CVE-2026-23737: seroval Remote Code Execution via JSON Deserialization

Source: https://junglewise.ai/threats/cve-2026-23737-lxsmnsyc-seroval-remote-code-execution-via-json-deserialization  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-01-21. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-23737 · Severity: low · CVSS 3.1 · Published 2026-01-21

seroval is a JavaScript library used to serialize and deserialize JavaScript values in web applications. A flaw in its JSON deserialization component allows an authenticated attacker to execute arbitrary JavaScript code on systems using affected versions. This could lead to data theft, session hijacking, or complete compromise of the application's security. Applications using seroval versions 1.4.0 and earlier are at risk and should upgrade immediately.

Technologies: [seroval (npm)](https://junglewise.ai/threats/technologies/seroval). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-23737 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-23737 being exploited in the wild.

**How severe is CVE-2026-23737?** 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-2026-23737?** 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-2026-23737 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-23737?** 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

  ```sh
  npm install seroval@1.4.1
  ```


## Technical details

The vulnerability exists in improper input validation (CWE-20) within seroval's JSON deserialization component. Specifically, the fromJSON and fromCrossJSON functions fail to properly validate deserialized data, allowing attackers to override constant values and manipulate error handling paths. This enables indirect access to unsafe JavaScript evaluation mechanisms. The attack requires: (1) authenticated access or ability to perform multiple requests to the same function, (2) high attack complexity, (3) partial knowledge of how serialized data is used at runtime, and (4) a client-to-server transmission scenario. An attacker can achieve confidentiality, integrity, and availability impact. The vulnerability is fixed in version 1.4.1 and later.

## Affected products

- lxsmnsyc seroval <1.4.1

## Identifiers

- CVE-2026-23737
- GHSA-3rxj-6cgf-8cfw

## Timeline

- 2026-01-21: disclosed: Vulnerability published as GHSA-3rxj-6cgf-8cfw and CVE-2026-23737
- 2026-01-21: patched: Patched in version 1.4.1

## References

- [https://github.com/lxsmnsyc/seroval/security/advisories/GHSA-3rxj-6cgf-8cfw](https://github.com/lxsmnsyc/seroval/security/advisories/GHSA-3rxj-6cgf-8cfw)
- [https://github.com/lxsmnsyc/seroval/commit/ce9408ebc87312fcad345a73c172212f2a798060](https://github.com/lxsmnsyc/seroval/commit/ce9408ebc87312fcad345a73c172212f2a798060)
- [https://github.com/lxsmnsyc/seroval](https://github.com/lxsmnsyc/seroval)

## Related threats

- [Seroval denial of service via array-like object in deserialization](https://junglewise.ai/threats/cve-2026-116584-seroval-facilitates-javascript-value-stringification-including)
- [Seroval typed array constructor name injection](https://junglewise.ai/threats/cve-2026-116583-seroval-facilitates-javascript-value-stringification-including)
- [Seroval JavaScript RegExp code injection in HTML script elements](https://junglewise.ai/threats/cve-2026-116582-seroval-facilitates-javascript-value-stringification-including)
- [Seroval improper sequence node validation in deserialization](https://junglewise.ai/threats/cve-2026-116581-seroval-facilitates-javascript-value-stringification-including)
- [Seroval incomplete fix for AsyncIterator deserialization bypass](https://junglewise.ai/threats/cve-2026-116580-seroval-facilitates-javascript-value-stringification-including)