{"cve":"CVE-2026-56763","nvd":{"published":"2026-07-11T14:16:22.080","modified":"2026-10-25T15:10:00.147","status":"Deferred","description":"Hono before 4.12.7 allows __proto__ key in parseBody with dot option enabled, permitting specially crafted form field names to create objects with __proto__ properties. When parsed results are merged into regular JavaScript objects using unsafe merge patterns, attackers can exploit this to achieve prototype pollution and modify object behavior.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","score":6.3},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","score":4.8},"cwes":["CWE-1321"],"references":["https://github.com/honojs/hono/security/advisories/GHSA-v8w9-8mx6-g223","https://www.vulncheck.com/advisories/hono-prototype-pollution-via-proto-key-in-parsebody-with-dot-option"],"products":[],"source":"nvd","synced_at":"2026-10-25T17:50:06.907763985+00:00"},"epss":{"cve":"CVE-2026-56763","score":0.00273,"percentile":0.19481,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-v8w9-8mx6-g223","url":"https://osv.dev/vulnerability/GHSA-v8w9-8mx6-g223","summary":"Hono vulnerable to Prototype Pollution possible through __proto__ key allowed in parseBody({ dot: true })","modified":"2026-10-02T22:45:04.525587715Z","packages":[{"ecosystem":"npm","name":"hono","purl":"pkg:npm/hono","ranges":["<4.12.7"],"fixed":["4.12.7"]}]}],"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."]}