{"schema":"threatline.record/2","record":{"id":"CVE-2021-48019","aliases":["GHSA-375m-5fvv-xq23"],"summary":"Vyper before 0.2.9 Incorrect RETURNDATASIZE in create_forwarder_to Proxies","details":"Vyper before 0.2.9 deploys forwarder proxies through the built-in create_forwarder_to function that report a fixed 4096-byte RETURNDATASIZE rather than the actual return data size. Calls through these proxies can yield corrupted data when a function returns more than 4096 bytes without return data sanitation, and fail strict return-size checks such as SafeERC20.safeTransfer.","categories":["Libraries & packages"],"product":"vyper","vendor":"vyperlang","ecosystem":"PyPI","affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2021-48019","source_modified_at":"2026-10-21T00:36:18.960Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"vyper","vendor":"vyperlang","versions":[{"lessThan":"0.2.9","status":"affected","version":"0","versionType":"python"},{"status":"unaffected","version":"0.2.9","versionType":"python"}],"defaultStatus":"unaffected"},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-375m-5fvv-xq23","source_modified_at":"2024-12-02T05:51:13.220757Z","fetched_at":"2026-10-23T18:48:36.087640Z","package":{"name":"vyper","ecosystem":"PyPI","purl":"pkg:pypi/vyper"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.2.9"}]}],"versions":["0.1.0b1","0.1.0b10","0.1.0b11","0.1.0b12","0.1.0b13","0.1.0b14","0.1.0b15","0.1.0b16","0.1.0b17","0.1.0b2","0.1.0b3","0.1.0b4","0.1.0b5","0.1.0b6","0.1.0b7","0.1.0b8","0.1.0b9","0.2.1","0.2.2","0.2.3","0.2.4","0.2.5","0.2.6","0.2.7","0.2.8"]}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2021-48019","source_modified_at":"2026-10-21T00:36:18.960Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"vyper","ecosystem":null},"version":"0.2.9","basis":"first unaffected version stated in the CVE record"},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-375m-5fvv-xq23","source_modified_at":"2024-12-02T05:51:13.220757Z","fetched_at":"2026-10-23T18:48:36.087640Z","package":{"name":"vyper","ecosystem":"PyPI","purl":"pkg:pypi/vyper"},"version":"0.2.9"}],"cvss":6.3,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.00248,"percentile":0.15176,"score_date":"2026-10-23"},"published_at":"2026-10-21T00:36:18.960Z","modified_at":"2026-10-21T00:36:18.960Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2021-48019","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-21T00:36:18.960Z"},{"source":"OSV","url":"https://osv.dev/vulnerability/GHSA-375m-5fvv-xq23","fetched_at":"2026-10-23T18:48:36.087640Z","source_modified_at":"2024-12-02T05:51:13.220757Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2021-48019","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","OSV","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/vyperlang/vyper/security/advisories/GHSA-375m-5fvv-xq23","tags":["vendor-advisory"]},{"source":"CVE List","url":"https://www.vulncheck.com/advisories/vyper-before-0.2.9-incorrect-returndatasize-in-create-forwarder-to-proxies","tags":["third-party-advisory"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"ecosystem","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-21T00:36:18.960Z","content_hash":"f1867f90cc2d37fda56ebb4535db182ec030a7e6b775a50aed7949678a8f23c4"}}