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.
History

Tue, 14 Jul 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Sat, 11 Jul 2026 13:30:00 +0000

Type Values Removed Values Added
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.
Title Hono - Prototype Pollution via __proto__ Key in parseBody with dot Option
First Time appeared Hono
Hono hono
Weaknesses CWE-1321
CPEs cpe:2.3:a:hono:hono:*:*:*:*:*:node.js:*:*
Vendors & Products Hono
Hono hono
References
Metrics cvssV3_1

{'score': 4.8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N'}

cvssV4_0

{'score': 6.3, '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'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published: 2026-07-11T13:00:59.084Z

Updated: 2026-07-14T14:30:12.573Z

Reserved: 2026-06-22T21:55:17.942Z

Link: CVE-2026-56763

cve-icon Vulnrichment

Updated: 2026-07-14T14:30:03.805Z

cve-icon NVD

No data.

cve-icon Redhat

No data.