Cyber Resilience

CVE-2026-47675

Medium

Published: 28 May 2026

Published
28 May 2026
Modified
29 May 2026
KEV Added
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Patch
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CVSS Score v3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
EPSS Score 0.0013 31.3th percentile
Risk Priority 9 60% EPSS · 20% KEV · 20% CVSS

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 Exploit Public-Facing Application (T1190); ranked at the 31.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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 TechniquesAI

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 →
Why these techniques?

Direct header injection in public web framework enables exploitation of exposed applications via crafted cookie attributes.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v18.1

Affected Assets

hono
hono
≤ 4.12.21

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References