CVE-2026-56763

Published: Jul 11, 2026Modified: Jul 14, 2026Deferred

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XShow less

Source: disclosure@vulncheck.com (Secondary)

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.

Related CWEs

CWE-1321

Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.

References (2)

https://github.com/honojs/hono/security/advisories/GHSA-v8w9-8mx6-g223

Source: disclosure@vulncheck.com

https://www.vulncheck.com/advisories/hono-prototype-pollution-via-proto-key-in-parsebody-with-dot-option

Source: disclosure@vulncheck.com

Timeline

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