Cyber Resilience

CVE-2026-47675

Hono ≤ 4.12.21

Published
28 May 2026
Modified
17 June 2026
Patch / advisory
View advisory
CVSS Score v3.1 4.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
EPSS Score 0.0022 12th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-47675 is a medium-severity HTTP Request/Response Splitting (CWE-113) vulnerability in Hono Hono. Its CVSS base score is 4.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Content Injection (T1659); ranked at the 12th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SI-15 (Information Output Filtering) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.21, the serialize() function in hono/cookie validates domain and path options against characters that corrupt Set-Cookie header syntax (;, \r, \n), but does not apply…

more

the same validation to sameSite and priority. An application that passes user-controlled input into either option may produce a Set-Cookie response header containing attacker-chosen additional attributes. This vulnerability is fixed in 4.12.21.

CWE(s)
CWE-113CWE-1287

Related Threats

MITRE ATT&CK Enterprise Techniques

T1659 Content Injection Initial Access
Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic.
attack.mitre.org →
T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-44459Same product: Hono Hono
CVE-2026-39410Same product: Hono Hono
CVE-2026-29085Same product: Hono Hono
CVE-2026-44458Same product: Hono Hono
CVE-2026-44455Same product: Hono Hono
CVE-2026-59895Same product: Hono Hono
CVE-2026-24771Same product: Hono Hono
CVE-2026-56761Same product: Hono Hono
CVE-2023-50710Same product: Hono Hono
CVE-2026-59896Same product: Hono Hono

Affected Assets

hono
hono
≤ 4.12.21

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V3.4.2
  • V4.1.3
  • V1.3.6
  • V4.2.3

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match

Input validation stops unneutralized CR/LF characters from being accepted and later emitted in HTTP headers.

SI-15 Information Output Filtering good match

Output filtering can neutralize CRLF sequences before they reach HTTP response headers.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require input sanitization and header handling that prevent CRLF injection.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development and acceptance can detect CRLF injection flaws before deployment.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates input validation and output encoding that directly prevents CRLF injection into HTTP headers.

A.8.26 Application security requirements partial match
prevents

Application security requirements explicitly call for controls against injection flaws including HTTP header manipulation.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles reduce the likelihood of header-splitting vulnerabilities through proper component isolation.

A.8.28 Secure coding partial match
prevents

Secure coding standards require neutralization of CRLF sequences before inclusion in HTTP headers.

A.8.15 Logging none match
none

Logging of HTTP traffic can record header-splitting attempts, aiding detection and forensics.

References