{"id":"CVE-2026-55451","sourceIdentifier":"security-advisories@github.com","published":"2026-09-14T17:17:48.383","lastModified":"2026-09-30T19:57:08.043","vulnStatus":"Deferred","cveTags":[],"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":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"locize","product":"gettext-converter","versions":[{"version":"< 1.3.3","status":"affected"}]}]}],"metrics":{"cvssMetricV40":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"4.0","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","baseScore":8.3,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-09-14T18:53:33.771788Z","id":"CVE-2026-55451","options":[{"exploitation":"poc"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-1321"}]}],"references":[{"url":"https://github.com/locize/gettext-converter/commit/df90c3b93e51faef68891d97b626544f619c5b31","source":"security-advisories@github.com"},{"url":"https://github.com/locize/gettext-converter/issues/15","source":"security-advisories@github.com"},{"url":"https://github.com/locize/gettext-converter/releases/tag/v1.3.3","source":"security-advisories@github.com"},{"url":"https://github.com/locize/gettext-converter/security/advisories/GHSA-f4jp-rw7w-ccwg","source":"security-advisories@github.com"},{"url":"https://github.com/locize/gettext-converter/issues/15","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}]}