Hono
CVE-2026-27700
HIGH
GHSA-xh87-mx6m-69f3
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessCraft HTTP request with malicious X-Forwarded-For header
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DeliveryALB appends real client IP to end
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ExploitgetConnInfo() reads first header value
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ExecutionIP restriction bypass achieved
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ImpactAccess control circumvented
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A07:2025 - Authentication Failures
ASVS 5.0
V6 - Authentication Anti-spoofing controls
MITRE ATT&CK
1 technique across 1 tactic: Defense Evasion The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Hono versions 4.12.0 or 4.12.1 using AWS Lambda adapter (hono/aws-lambda) deployed behind AWS Application Load Balancer (ALB) with IP-based access control middleware (ipRestriction) enabled |
| Impact | CVSS 8.2 (HIGH). Attack vector: Network. Complexity: Low. Privileges required: None. User interaction: None. |
| Exploit ScenarioDerived | An attacker could exploit this vulnerability to IP-based access control mechanisms (such as the |
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Alert meAnalysisAIv1 – Mar 12, 2026
Hono is a Web application framework that provides support for any JavaScript runtime. [CVSS 8.2 HIGH]
RemediationAI
A vendor patch is available — apply it immediately. Restrict network access to the affected service where possible.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in npm
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
Classified as CWE-290 (Authentication Bypass by Spoofing). Affects Hono. Hono is a Web application framework that provides support for any JavaScript runtime. In versions 4.12.0 and 4.12.1, when using the AWS Lambda adapter (hono/aws-lambda) behind an Application Load Balancer (ALB), the getConnInfo() function incorrectly selected the first value from the X-Forwarded-For header. Because AWS ALB appends the real client IP address to the end of the X-Forwarded-For header, the first value can be attacker-controlled. This could allow IP-based access control mecha
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
Primary rating from GitHub Advisory · only source for this CVE.
CVSS VectorGitHub Advisory
Lifecycle Timeline
2DescriptionGitHub Advisory
Hono is a Web application framework that provides support for any JavaScript runtime. In versions 4.12.0 and 4.12.1, when using the AWS Lambda adapter (hono/aws-lambda) behind an Application Load Balancer (ALB), the getConnInfo() function incorrectly selected the first value from the X-Forwarded-For header. Because AWS ALB appends the real client IP address to the end of the X-Forwarded-For header, the first value can be attacker-controlled. This could allow IP-based access control mechanisms (such as the ipRestriction middleware) to be bypassed. Version 4.12.2 patches the issue.
Blast Radius
ecosystem impact- 7 npm packages depend on hono (4 direct, 3 indirect)
Ecosystem-wide dependent count for version 4.12.0.
Executive ViewAI
A HIGH severity vulnerability (CVE-2026-27700) exists in Hono web application framework affecting any JavaScript runtime environments. Organizations using Hono-based applications face potential compromise of application integrity and data confidentiality. Immediate patching is required to prevent exploitation.
Apply vendor patch.
Threat Intelligence Overview
NVD
CVE.org
EPSS
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Affected Products (CPE)GitHub Advisory
Improper authorization in Hono's JWT Auth Middleware (hono/jwt in the npm package 'hono', versions 1.1.0 through 4.10.1)
The adapter @hono/node-server allows you to run your Hono application on Node.js. Rated high severity (CVSS 7.5), this v
Hono, a web framework, prior to version 4.6.5 is vulnerable to bypass of cross-site request forgery (CSRF) middleware by
Quadratic-complexity denial of service in Hono's `languageDetector` middleware (versions 4.12.0-4.12.33) allows unauthen
Path prefix stripping in Hono's app.mount() API exposes mounted sub-applications to incorrect routing due to a raw-vs-de
Hono is a Web application framework that provides support for any JavaScript runtime. Rated medium severity (CVSS 5.3),
@hono/node-server is an adapter that allows users to run Hono applications on Node.js. Rated medium severity (CVSS 5.3),
Hono is a Web application framework that provides support for any JavaScript runtime. Rated medium severity (CVSS 5.0),
Cross-user HTML disclosure in Hono's server-side rendering affects all applications using hono/jsx with memo()-wrapped c
Hono is a web framework written in TypeScript. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploita
Hono versions before 4.11.4 allow JWT algorithm confusion attacks through improper algorithm validation in the JWK/JWKS
Hono before version 4.11.4 contains a JWT algorithm confusion vulnerability in its JWK/JWKS verification middleware that
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