What is the CVSS score of CVE-2026-29085?

CVE-2026-29085 has a CVSS 3.1 base score of 6.5 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N. EPSS exploitation probability: 0.1%.

Which versions of Hono are affected by CVE-2026-29085?

Organizations using Hono should be aware of notable risk from CVE-2026-29085, a injection vulnerability rated CVSS 6.5. Exploitation could allow attackers to execute code or inject malicious input.. A patch is available.

How to fix or mitigate CVE-2026-29085?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Validate input sanitization for user-controlled parameters.

Hono CVE-2026-29085

MEDIUM

Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') (CWE-74)

2026-03-04 security-advisories@github.com

GHSA-p6xx-57qc-3wxr

Code Injection Hono

6.5

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

6.5 MEDIUM

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

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:05 vuln.today

Patch released

Mar 06, 2026 - 18:03 nvd

Patch available

CVE Published

Mar 04, 2026 - 23:16 nvd

MEDIUM 6.5

Blast Radius

ecosystem impact

† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth

10 npm packages depend on hono (10 direct, 0 indirect)

Ecosystem-wide dependent count for version 4.12.4.

DescriptionGitHub Advisory

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.

AnalysisAI

Hono versions up to 4.12.4 contains a vulnerability that allows attackers to injection of additional SSE fields within the same event frame if untrusted inpu (CVSS 6.5).

Technical ContextAI

affects Hono. 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.