TI-2026-23229 Aliases CVE-2026-29085 GHSA-p6xx-57qc-3wxr

Hono: SSE Control Field Injection via CR/LF in writeSSE()

LOW 35CWE-74Published 2026-03-04 · Updated 2026-03-05

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: Low · Low · None
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00281 20th percentileScored 2026-11-07

Fix Fixed hono (honojs): 4.12.4hono (npm): 4.12.4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
honojs	hono	before 4.12.4	4.12.4	Patch available	CNA
—	hono (npm)	before 4.12.4	4.12.4	Patch available	GHSA-p6xx-57qc-3wxr

hono Vendorhonojs Affected before 4.12.4 Fixed in 4.12.4 Patch available CNA
hono (npm) Vendor— Affected before 4.12.4 Fixed in 4.12.4 Patch available GHSA-p6xx-57qc-3wxr

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:hono:hono::::::node.js::*	before 4.12.4	Vulnerable	honojs

cpe:2.3:a:hono:hono:*:*:*:*:*:node.js:*:* Versions before 4.12.4 Vulnerable ·honojs

Remediation

Fix · CNA hono (honojs) Fixed in 4.12.4
Fix · GHSA-p6xx-57qc-3wxr hono (npm) Fixed in 4.12.4 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-29085
2026-10-03 Alias added: GHSA-p6xx-57qc-3wxr

References

Patch 1

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

Advisory 2

Other 1

https://github.com/honojs/hono

TI-2024-21741 Hono vulnerable to Restricted Directory Traversal in serveStatic with deno CVSS 3.1MEDIUM 5.3
TI-2024-32610 Hono vulnerable to bypass of CSRF Middleware by a request without Content-Type header. CVSS 3.1MEDIUM 5.9
TI-2024-29381 Hono CSRF middleware can be bypassed using crafted Content-Type header CVSS 3.1MEDIUM 5.0
TI-2026-23190 Hono: Arbitrary file access via serveStatic vulnerability CVSS 3.1CRITICAL 9.8
TI-2026-22076 Hono is Vulnerable to Authentication Bypass by IP Spoofing in AWS Lambda ALB conninfo CVSS 3.1HIGH 8.2
TI-2026-18334 JWT algorithm confusion in Hono JWK Auth Middleware when JWK lacks "alg" (untrusted header.alg fallback) CVSS 3.1HIGH 8.2

See all 33 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences