CVE-2026-55451: Locize Gettext-Converter

High severity, CVSS 8.3. EPSS: 0.6% chance of exploitation in the next 30 days.

gettext-converter provides gettext resource conversion utilities for JavaScript. Prior to 1.3.3, js2i18next() in lib/js2i18next.js splits nested translation keys using options.keyseparator, whose default value consists of two number signs, and uses each segment as a dynamic object key without rejecting __proto__, constructor, or prototype. When an application converts untrusted PO or i18next translation data, a __proto__ segment resolves Object.prototype as the nested write target and Object.assign writes attacker-controlled translated properties onto the process-wide prototype. The resulting prototype pollution can cause denial of service and may enable application-dependent follow-on attacks. This issue is fixed in version 1.3.3.

Affected products

• Locize Gettext-Converter: before 1.3.3 (fixed in 1.3.3)

Published 2026-09-14. Last modified 2026-09-30.