CVE-2025-57350 is a prototype pollution vulnerability identified in the csvtojson package, a widely used tool for converting CSV data into JSON format with customizable parsing features. The vulnerability exists in versions prior to 2.0.10, specifically within the parser_jsonarray component responsible for handling CSV headers. The root cause is insufficient sanitization of nested header names, allowing specially crafted CSV headers that include prototype chain references such as '__proto__' to manipulate the base Object prototype in JavaScript. This manipulation can alter or inject properties into the global Object prototype, which affects all objects inheriting from it. Such prototype pollution can lead to denial of service (DoS) conditions or cause unpredictable behavior in applications that rely on the integrity of prototype chains. Importantly, exploitation does not require user interaction beyond supplying a malicious CSV file, making automated or remote exploitation feasible in scenarios where untrusted CSV data is processed. While no known exploits are currently reported in the wild, the vulnerability poses a significant risk to applications that parse CSV inputs without adequate validation or sanitization. The absence of a CVSS score indicates this is a newly published vulnerability, reserved in August 2025 and published in September 2025, with no patch links currently available, suggesting that remediation efforts may still be underway or pending release.

For European organizations, the impact of CVE-2025-57350 can be substantial, especially for those relying on the csvtojson package in their data processing pipelines, analytics platforms, or web applications that ingest CSV data from external or untrusted sources. Prototype pollution can compromise application integrity by corrupting internal object states, potentially leading to application crashes, denial of service, or erratic behavior that undermines data processing reliability. This can disrupt business operations, cause data processing errors, or open indirect avenues for further exploitation if attackers leverage the polluted prototype to escalate privileges or bypass security controls. Organizations in sectors such as finance, healthcare, manufacturing, and government, which often handle large volumes of CSV data for reporting or integration, are particularly at risk. Additionally, the ease of exploitation without user interaction increases the threat surface, as attackers can automate attacks by submitting malicious CSV files through exposed interfaces or APIs. The lack of immediate patches means organizations must act proactively to mitigate risk. Failure to address this vulnerability could lead to operational downtime, reputational damage, and potential regulatory compliance issues under frameworks like GDPR if data integrity or availability is compromised.

To mitigate CVE-2025-57350 effectively, European organizations should implement the following specific measures: 1) Immediately audit all applications and services that utilize the csvtojson package, identifying versions prior to 2.0.10 and prioritizing their update once a patched version is released. 2) Until patches are available, implement input validation and sanitization controls to detect and reject CSV files containing suspicious header fields, particularly those with '__proto__' or other prototype chain references. 3) Employ runtime application self-protection (RASP) or web application firewalls (WAFs) with custom rules to monitor and block attempts to exploit prototype pollution via CSV inputs. 4) Isolate CSV processing components in sandboxed or containerized environments to limit the impact of potential exploitation on broader systems. 5) Conduct code reviews and static analysis to identify other potential prototype pollution vectors within the codebase. 6) Enhance logging and monitoring around CSV ingestion points to detect anomalous behavior indicative of exploitation attempts. 7) Educate development and security teams about prototype pollution risks and secure coding practices related to object property handling in JavaScript. These targeted actions go beyond generic advice by focusing on immediate risk reduction through input controls and environment isolation while preparing for patch deployment.