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OpenAdvisories
High · 7.5 CVE-2025-57349 EUVD-2025-31065GHSA-xfqm-j7pc-xrfc

messageformat has a prototype pollution vulnerability

Published Sep 24, 2025 · Updated Sep 29, 2025 · Assigned by mitre

Description

The messageformat package, an implementation of the Unicode MessageFormat 2 specification for JavaScript, is vulnerable to prototype pollution due to improper handling of message key paths in versions prior to 2.3.0. The flaw arises when processing nested message keys containing special characters (e.g., __proto__ ), which can lead to unintended modification of the JavaScript Object prototype. This vulnerability may allow a remote attacker to inject properties into the global object prototype via specially crafted message input, potentially causing denial of service or other undefined behaviors in applications using the affected component.

Affected packages

EcosystemPackageAffectedFixedRecord
npm messageformat < 3.0.0-beta.0 3.0.0-beta.0 GHSA-xfqm-j7pc-xrfc

References