CVE-2026-23736: seroval Affected by Prototype Pollution via JSON Deserialization

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% 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-1321

Description

seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities. In versions 1.4.0 and below, due to improper input validation, a malicious object key can lead to prototype pollution during JSON deserialization. This vulnerability affects only JSON deserialization functionality. This issue is fixed in version 1.4.1.

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

https://github.com/lxsmnsyc/seroval/commit/ce9408ebc87312fcad345a73c172212f2a798060
https://github.com/lxsmnsyc/seroval/security/advisories/GHSA-hj76-42vx-jwp4

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