Improper Validation of Unsafe Equivalence in Input in hono - CVE-2026-47674
Published: July 24, 2026
Vulnerability identifier: #VU139278
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-47674
CWE-ID: CWE-1289
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to bypass IP-based access controls.
The vulnerability exists due to improper validation of unsafe equivalence in input in the ip-restriction middleware when handling requests with non-canonical IPv6 source addresses against static deny rules. A remote attacker can supply a non-canonical representation of a denied IP address to bypass IP-based access controls.
This issue occurs when applications use static non-CIDR rules and the IP address source can provide non-canonical IPv6 forms, such as compressed or expanded notation, IPv4-mapped hexadecimal notation, or zone identifier suffixes.
Affected software
hono
How to mitigate CVE-2026-47674
Install security update from vendor's website.
hono - update to 4.12.21