{"id":"CVE-2026-55451","state":"PUBLISHED","title":"gettext-converter: Prototype pollution in js2i18next() via crafted translation keys","description":"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.","publishedAt":"2026-09-14T16:49:36.238Z","updatedAt":"2026-09-14T18:53:39.960Z","severity":{"score":8.3,"label":"High","version":"4.0","vector":"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","source":"GitHub_M"},"assigner":"GitHub_M","products":["locize gettext-converter"],"affected":[{"vendor":"locize","product":"gettext-converter","versions":[{"version":"< 1.3.3","status":"affected"}]}],"references":["https://github.com/locize/gettext-converter/security/advisories/GHSA-f4jp-rw7w-ccwg","https://github.com/locize/gettext-converter/issues/15","https://github.com/locize/gettext-converter/commit/df90c3b93e51faef68891d97b626544f619c5b31","https://github.com/locize/gettext-converter/releases/tag/v1.3.3"],"weaknesses":["CWE-1321"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/55xxx/CVE-2026-55451.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55451","state":"PUBLISHED","datePublished":"2026-09-14T16:49:36.238Z","dateUpdated":"2026-09-14T18:53:39.960Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-16T21:59:57.018Z"},"containers":{"cna":{"title":"gettext-converter: Prototype pollution in js2i18next() via crafted translation keys","descriptions":[{"lang":"en","value":"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":[{"vendor":"locize","product":"gettext-converter","versions":[{"version":"< 1.3.3","status":"affected"}]}],"references":[{"url":"https://github.com/locize/gettext-converter/security/advisories/GHSA-f4jp-rw7w-ccwg","name":"https://github.com/locize/gettext-converter/security/advisories/GHSA-f4jp-rw7w-ccwg","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/locize/gettext-converter/issues/15","name":"https://github.com/locize/gettext-converter/issues/15","tags":["x_refsource_MISC"]},{"url":"https://github.com/locize/gettext-converter/commit/df90c3b93e51faef68891d97b626544f619c5b31","name":"https://github.com/locize/gettext-converter/commit/df90c3b93e51faef68891d97b626544f619c5b31","tags":["x_refsource_MISC"]},{"url":"https://github.com/locize/gettext-converter/releases/tag/v1.3.3","name":"https://github.com/locize/gettext-converter/releases/tag/v1.3.3","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.3,"baseSeverity":"HIGH","vectorString":"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","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-1321","lang":"en","description":"CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-14T16:49:36.238Z"},"source":{"advisory":"GHSA-f4jp-rw7w-ccwg","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/locize/gettext-converter/issues/15","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-14T18:53:33.771788Z","id":"CVE-2026-55451","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-14T18:53:39.960Z"}}]}}}