{"id":"EUVD-2026-13881","revision":"a2bbecff7dfa42ff86fa84a2f3bded7e","records":[{"revision":"a2bbecff7dfa42ff86fa84a2f3bded7e","observedAt":"2026-11-09T08:10:03.226+00:00","statement":{"source":"euvd","id":"EUVD-2026-13881","aliases":["CVE-2026-33228","GHSA-rf6f-7fwh-wjgh"],"title":"flatted is a circular JSON parser. Prior to version 3.4.2, the parse() function in flatted can use attacker-controlled string values from the parsed JSON as direct array index keys, without validating that they are numeric. Since the intern…","description":"flatted is a circular JSON parser. Prior to version 3.4.2, the parse() function in flatted can use attacker-controlled string values from the parsed JSON as direct array index keys, without validating that they are numeric. Since the internal input buffer is a JavaScript Array, accessing it with the key \"__proto__\" returns Array.prototype via the inherited getter. This object is then treated as a legitimate parsed value and assigned as a property of the output object, effectively leaking a live reference to Array.prototype to the consumer. Any code that subsequently writes to that property will pollute the global prototype. This issue has been patched in version 3.4.2.","state":0,"publishedAt":null,"modifiedAt":null,"affected":[],"metrics":[{"system":"EUVD CVSS 4.0","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","score":8.9,"severity":null}],"references":["https://github.com/WebReflection/flatted/security/advisories/GHSA-rf6f-7fwh-wjgh","https://github.com/WebReflection/flatted/commit/885ddcc33cf9657caf38c57c7be45ae1c5272802","https://github.com/WebReflection/flatted/releases/tag/v3.4.2"],"sourceUrl":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-13881","license":"ENISA EUVD · source terms and attribution apply","enrichment":{"sourceStatus":null,"weaknesses":[],"productCriteria":[],"sourceDates":{"datePublished":"Mar 20, 2026, 11:06:48 PM","dateUpdated":"Sep 7, 2026, 12:05:12 PM"},"relatedAdvisories":[{"id":"msrc_CVE-2026-33228","title":"flatted: Prototype Pollution via parse()","vulnerabilityIds":["CVE-2026-33228"]},{"id":"RHSA-2026:86618","title":"Red Hat Security Advisory: New container image: rhceph-9.2","vulnerabilityIds":["CVE-2023-46159","CVE-2024-47866","CVE-2024-48916","CVE-2024-55565","CVE-2025-12816","CVE-2025-15599","CVE-2025-26791","CVE-2025-30156","CVE-2025-50181","CVE-2025-50182","CVE-2025-58754","CVE-2025-59343","CVE-2025-62718","CVE-2025-66030","CVE-2025-66035","CVE-2025-66412","CVE-2025-69873","CVE-2026-0540","CVE-2026-21441","CVE-2026-22610","CVE-2026-25639","CVE-2026-26996","CVE-2026-27903","CVE-2026-27904","CVE-2026-27970","CVE-2026-32141","CVE-2026-33228","CVE-2026-33671","CVE-2026-33672","CVE-2026-33891","CVE-2026-33894","CVE-2026-33895","CVE-2026-33896","CVE-2026-39865","CVE-2026-40175","CVE-2026-40895","CVE-2026-41238","CVE-2026-41239","CVE-2026-41240","CVE-2026-41305","CVE-2026-42033","CVE-2026-42034","CVE-2026-42035","CVE-2026-42036","CVE-2026-42037","CVE-2026-42038","CVE-2026-42039","CVE-2026-42040","CVE-2026-42041","CVE-2026-42042","CVE-2026-42043","CVE-2026-42044","CVE-2026-50152","CVE-2026-58224"]},{"id":"RHSA-2026:9742","title":"Red Hat Security Advisory: Red Hat Developer Hub 1.8.6 release.","vulnerabilityIds":["CVE-2025-62718","CVE-2025-69534","CVE-2025-69873","CVE-2026-1525","CVE-2026-1526","CVE-2026-1528","CVE-2026-2229","CVE-2026-3118","CVE-2026-4800","CVE-2026-4926","CVE-2026-25679","CVE-2026-26996","CVE-2026-27601","CVE-2026-27904","CVE-2026-29063","CVE-2026-29074","CVE-2026-29186","CVE-2026-32141","CVE-2026-33036","CVE-2026-33228","CVE-2026-33891","CVE-2026-33894","CVE-2026-33895","CVE-2026-33896","CVE-2026-39983","CVE-2026-40175"]},{"id":"RHSA-2026:34342","title":"Red Hat Security Advisory: Cluster Observability Operator 1.5.0","vulnerabilityIds":["CVE-2020-7753","CVE-2021-33623","CVE-2024-4068","CVE-2024-45338","CVE-2024-52011","CVE-2025-22868","CVE-2025-22870","CVE-2025-22872","CVE-2025-47911","CVE-2025-58190","CVE-2026-1526","CVE-2026-1528","CVE-2026-2229","CVE-2026-4800","CVE-2026-4867","CVE-2026-6321","CVE-2026-6322","CVE-2026-6734","CVE-2026-9277","CVE-2026-9697","CVE-2026-12143","CVE-2026-12151","CVE-2026-25680","CVE-2026-25681","CVE-2026-29063","CVE-2026-32141","CVE-2026-33228","CVE-2026-33671","CVE-2026-33814","CVE-2026-33891","CVE-2026-33894","CVE-2026-33895","CVE-2026-33896","CVE-2026-33937","CVE-2026-33938","CVE-2026-33939","CVE-2026-33940","CVE-2026-33941","CVE-2026-39821","CVE-2026-42506","CVE-2026-48779"]},{"id":"RHSA-2026:13826","title":"Red Hat Security Advisory: Red Hat Developer Hub 1.9.4 release.","vulnerabilityIds":["CVE-2025-62718","CVE-2025-69534","CVE-2026-1525","CVE-2026-1526","CVE-2026-1528","CVE-2026-2229","CVE-2026-3118","CVE-2026-4800","CVE-2026-4926","CVE-2026-27601","CVE-2026-27904","CVE-2026-29063","CVE-2026-29074","CVE-2026-29186","CVE-2026-32141","CVE-2026-32280","CVE-2026-32282","CVE-2026-33228","CVE-2026-33891","CVE-2026-33894","CVE-2026-33895","CVE-2026-33896","CVE-2026-39983","CVE-2026-40175","CVE-2026-40895"]}],"note":"EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON."},"key":"euvd:EUVD-2026-13881","identifiers":["EUVD-2026-13881","CVE-2026-33228","GHSA-rf6f-7fwh-wjgh"]},"retained":false,"historicalAffected":[]}],"coverage":[]}