What’s Vulnerable › Vulnerabilities

CVE-2026-42241: ParquetSharp: Possible Stack Overflow When Reading a ParquetFile with Large Decimal Type Width

• Severity: medium (CVSS 5.3 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: 2026-05-07 · updated 2026-10-26
• Weakness: CWE-789

Description

ParquetSharp is a .NET library for reading and writing Apache Parquet files. From version 18.1.0 to before version 23.0.0.1, DecimalConverter.ReadDecimal makes a stackalloc using what might be an attacker-supplied value. If an attacker declares a decimal column with some unreasonable width, this could lead to a stack overflow. In a service environment, this would potentially take down a service. This affects applications using ParquetSharp to read untrusted Parquet files in a network service. This issue has been patched in version 23.0.0.1.

Affected products

• G-Research ParquetSharp: from 18.1.0, < 23.0.0.1

References

• https://github.com/G-Research/ParquetSharp/releases/tag/23.0.0.1
• https://github.com/G-Research/ParquetSharp/security/advisories/GHSA-rrjr-v56m-ww88

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