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

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-01-21 · updated 2026-06-17
Weakness: CWE-502

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.

Affected products

lxsmnsyc seroval: before 1.4.1 — fixed in 1.4.1

How to fix

Upgrade to a fixed version: lxsmnsyc seroval 1.4.1. Check the vendor advisory for mitigations.

References

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