Insufficient verification of data authenticity in hono - CVE-2026-27700
Published: July 24, 2026
Vulnerability identifier: #VU139315
CSH Severity: High
CVSS v4: 8.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-27700
CWE-ID: CWE-345
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to bypass IP-based access restrictions.
The vulnerability exists due to insufficient verification of data authenticity in the getConnInfo() function of the AWS Lambda adapter when processing the X-Forwarded-For header behind an Application Load Balancer. A remote attacker can supply a crafted X-Forwarded-For header to bypass IP-based access restrictions.
Only deployments using the AWS Lambda adapter behind an Application Load Balancer and relying on getConnInfo() for IP-based authorization decisions are affected.
Affected software
hono
How to mitigate CVE-2026-27700
Install security update from vendor's website.
hono - update to 4.12.2