{"cve":"CVE-2021-46878","nvd":{"published":"2023-04-11T18:15:58.340","modified":"2026-06-17T04:15:43.120","status":"Modified","description":"An issue was discovered in Treasure Data Fluent Bit 1.7.1, erroneous parsing in flb_pack_msgpack_to_json_format leads to type confusion bug that interprets whatever is on the stack as msgpack maps and arrays, leading to use-after-free. This can be used by an attacker to craft a specially craft file and trick the victim opening it using the affect software, triggering use-after-free and execute arbitrary code on the target system.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-843"],"references":["https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=27742","https://github.com/fluent/fluent-bit/pull/3115","https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=27742","https://github.com/fluent/fluent-bit/pull/3115"],"products":["treasuredata:fluent_bit"],"source":"nvd","synced_at":"2026-10-19T21:38:05.473481323+00:00"},"epss":{"cve":"CVE-2021-46878","score":0.0035,"percentile":0.28648,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}