CVE-2026-23737
Unknown Unknown - Not Provided
Arbitrary Code Execution in seroval JSON Deserialization

Publication date: 2026-01-21

Last updated on: 2026-02-27

Assigner: GitHub, Inc.

Description
seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities. In versions 1.4.0 and below, improper input handling in the JSON deserialization component can lead to arbitrary JavaScript code execution. Exploitation is possible via overriding constant value and error deserialization, allowing indirect access to unsafe JS evaluation. At minimum, attackers need the ability to perform 4 separate requests on the same function, and partial knowledge of how the serialized data is used during later runtime processing. This vulnerability affects the fromJSON and fromCrossJSON functions in a client-to-server transmission scenario. This issue has been fixed in version 1.4.0.
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Meta Information
Published
2026-01-21
Last Modified
2026-02-27
Generated
2026-06-16
AI Q&A
2026-01-22
EPSS Evaluated
2026-06-14
NVD
CVE-2026-23737
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
lxsmnsyc seroval to 1.4.1 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-502 The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
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Executive Summary

This vulnerability exists in seroval versions 1.4.0 and below, where improper input handling in the JSON deserialization component can lead to arbitrary JavaScript code execution. Specifically, exploitation is possible by overriding constant value and error deserialization, which allows indirect access to unsafe JavaScript evaluation. The affected functions are fromJSON and fromCrossJSON in a client-to-server transmission scenario. Attackers need to perform at least 4 separate requests on the same function and have partial knowledge of how the serialized data is used during runtime.

Impact Analysis

This vulnerability can lead to arbitrary JavaScript code execution on the server side, which can compromise confidentiality, integrity, and availability of the affected system. An attacker could execute malicious code remotely, potentially leading to data breaches, unauthorized access, or disruption of services.

Mitigation Strategies

Upgrade seroval to version 1.4.0 or later, as this version contains the fix for the vulnerability. Additionally, restrict the ability of attackers to perform multiple requests on the same function and limit exposure of serialized data handling during runtime processing.

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