{"id":"CVE-2026-55451","summary":"gettext-converter: Prototype pollution in js2i18next() via crafted translation keys","details":"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.","aliases":["GHSA-f4jp-rw7w-ccwg"],"modified":"2026-09-16T03:46:58.929135454Z","published":"2026-09-14T16:49:36.238Z","database_specific":{"cwe_ids":["CWE-1321"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55451.json","cna_assigner":"GitHub_M"},"references":[{"type":"WEB","url":"https://github.com/locize/gettext-converter/releases/tag/v1.3.3"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55451.json"},{"type":"ADVISORY","url":"https://github.com/locize/gettext-converter/security/advisories/GHSA-f4jp-rw7w-ccwg"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55451"},{"type":"REPORT","url":"https://github.com/locize/gettext-converter/issues/15"},{"type":"FIX","url":"https://github.com/locize/gettext-converter/commit/df90c3b93e51faef68891d97b626544f619c5b31"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/locize/gettext-converter","events":[{"introduced":"0"},{"fixed":"df90c3b93e51faef68891d97b626544f619c5b31"},{"fixed":"4b02e8c5c2a873b638a4d90bd8459213ba323724"}],"database_specific":{"source":["AFFECTED_FIELD","REFERENCES"],"extracted_events":[{"introduced":"0"},{"fixed":"1.3.3"}]}}],"versions":["v1.3.2","v1.3.1","v1.3.0","v1.2.4","v1.2.3","v1.2.2","v1.2.1","v1.2.0","v1.1.3","v1.1.2","v1.1.1","v1.1.0","v1.0.8","v1.0.7","v1.0.6","v1.0.5","v1.0.4","v1.0.3","v1.0.2","v1.0.1","v1.0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55451.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N"}]}