CVE-2026-29085
Hono: SSE Control Field Injection via CR/LF in writeSSE()
- State
- Published
- Severity
- 6.5 Medium
- Published
- Mar 4, 2026
- Updated
- Mar 5, 2026
- Reserved
- Mar 3, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 6.5 Medium | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N | GitHub_M |
Weaknesses
- CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
Affected Products
| Product | Versions |
|---|---|
honohonojs |
|
References
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