CVE-2026-29085

Published: Mar 4, 2026Modified: Jun 17, 2026

6.5

Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Exploitability: 3.9 / Impact: 2.5

Source: security-advisories@github.com (Secondary)

Description

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to version 4.12.4, when using streamSSE() in Streaming Helper, the event, id, and retry fields were not validated for carriage return (\r) or newline (\n) characters. Because the SSE protocol uses line breaks as field delimiters, this could allow injection of additional SSE fields within the same event frame if untrusted input was passed into these fields. This issue has been patched in version 4.12.4.

Affected (1)

Products: Hono: Hono

1 product

Configuration A

1 vulnerable

Vulnerable Software	Affected Versions
Hono Hono	Before 4.12.4

Related CWEs

Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.

References (2)

https://github.com/honojs/hono/commit/f4123ed9ea3c7c52380cc99a079a4d773838846e

Source: security-advisories@github.com

Patch

https://github.com/honojs/hono/security/advisories/GHSA-p6xx-57qc-3wxr

Source: security-advisories@github.com

Vendor Advisory

Timeline

No history available yet.