CVE-2025-27597: Vue I18n Prototype Pollution in `handleFlatJson`
Description
Vue I18n is the internationalization plugin for Vue.js. @intlify/message-resolver and @intlify/vue-i18n-core are vulnerable to Prototype Pollution through the entry function: handleFlatJson. An attacker can supply a payload with Object.prototype setter to introduce or modify properties within the global prototype chain, causing denial of service (DoS) a the minimum consequence. Moreover, the consequences of this vulnerability can escalate to other injection-based attacks, depending on how the library integrates within the application. For instance, if the polluted property propagates to sensitive Node.js APIs (e.g., exec, eval), it could enable an attacker to execute arbitrary commands within the application's context.
Classification
CVE ID: CVE-2025-27597
CVSS Base Severity: HIGH
CVSS Base Score: 8.9
CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
Problem Types
CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')Affected Products
Vendor: intlify
Product: vue-i18n
Exploit Prediction Scoring System (EPSS)
EPSS Score: 0.09% (probability of being exploited)
EPSS Percentile: 22.25% (scored less or equal to compared to others)
EPSS Date: 2025-04-05 (when was this score calculated)
References
https://nvd.nist.gov/vuln/detail/CVE-2025-27597https://github.com/intlify/vue-i18n/security/advisories/GHSA-p2ph-7g93-hw3m
https://github.com/intlify/vue-i18n/commit/4bb6eacda7fc2cde5687549afa0efb27ca40862a