1. Home
  2. Vulnerabilities
  3. CVE-2026-27700
8.2
HIGH CVSS 3.1
CVE-2026-27700
Hono is Vulnerable to Authentication Bypass by IP Spoofing in AWS Lambda ALB conninfo
Description

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.

INFO

Published Date :

Feb. 25, 2026, 4:23 p.m.

Last Modified :

March 2, 2026, 4:17 p.m.

Remotely Exploit :

Yes !

Source :

[email protected]
Affected Products

The following products are affected by CVE-2026-27700 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Hono hono
: Total Affected Vendor : 1 | Products : 1
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH [email protected]
CVSS 3.1 HIGH MITRE-CVE
CVSS 3.1 HIGH [email protected]
Solution
Update Hono to version 4.12.2 to fix incorrect IP address handling with AWS Lambda adapter.
  • Update Hono to version 4.12.2.
  • Ensure AWS Lambda adapter configuration is correct.
  • Verify IP-based access control mechanisms.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-27700.

URL Resource
https://github.com/honojs/hono/commit/41adbf56e252c04611f8972364ac0887ae07a4c7 Patch
https://github.com/honojs/hono/releases/tag/v4.12.2 ProductRelease Notes
https://github.com/honojs/hono/security/advisories/GHSA-xh87-mx6m-69f3 Vendor Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-27700 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-27700 weaknesses.

CAPEC-21: Exploitation of Trusted Identifiers Exploitation of Trusted Identifiers CAPEC-22: Exploiting Trust in Client Exploiting Trust in Client CAPEC-59: Session Credential Falsification through Prediction Session Credential Falsification through Prediction CAPEC-60: Reusing Session IDs (aka Session Replay) Reusing Session IDs (aka Session Replay) CAPEC-94: Adversary in the Middle (AiTM) Adversary in the Middle (AiTM) CAPEC-459: Creating a Rogue Certification Authority Certificate Creating a Rogue Certification Authority Certificate CAPEC-461: Web Services API Signature Forgery Leveraging Hash Function Extension Weakness Web Services API Signature Forgery Leveraging Hash Function Extension Weakness CAPEC-473: Signature Spoof Signature Spoof CAPEC-476: Signature Spoofing by Misrepresentation Signature Spoofing by Misrepresentation CAPEC-667: Bluetooth Impersonation AttackS (BIAS) Bluetooth Impersonation AttackS (BIAS) CAPEC-111: JSON Hijacking (aka JavaScript Hijacking) JSON Hijacking (aka JavaScript Hijacking) CAPEC-141: Cache Poisoning Cache Poisoning CAPEC-142: DNS Cache Poisoning DNS Cache Poisoning CAPEC-148: Content Spoofing Content Spoofing CAPEC-218: Spoofing of UDDI/ebXML Messages Spoofing of UDDI/ebXML Messages CAPEC-384: Application API Message Manipulation via Man-in-the-Middle Application API Message Manipulation via Man-in-the-Middle CAPEC-385: Transaction or Event Tampering via Application API Manipulation Transaction or Event Tampering via Application API Manipulation CAPEC-386: Application API Navigation Remapping Application API Navigation Remapping CAPEC-387: Navigation Remapping To Propagate Malicious Content Navigation Remapping To Propagate Malicious Content CAPEC-388: Application API Button Hijacking Application API Button Hijacking CAPEC-665: Exploitation of Thunderbolt Protection Flaws Exploitation of Thunderbolt Protection Flaws CAPEC-701: Browser in the Middle (BiTM) Browser in the Middle (BiTM)

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-27700 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-27700 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Mar. 02, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
    Added CWE CWE-290
    Added CPE Configuration OR *cpe:2.3:a:hono:hono:*:*:*:*:*:node.js:*:* versions from (including) 4.12.0 up to (excluding) 4.12.2
    Added Reference Type GitHub, Inc.: https://github.com/honojs/hono/commit/41adbf56e252c04611f8972364ac0887ae07a4c7 Types: Patch
    Added Reference Type GitHub, Inc.: https://github.com/honojs/hono/releases/tag/v4.12.2 Types: Product, Release Notes
    Added Reference Type GitHub, Inc.: https://github.com/honojs/hono/security/advisories/GHSA-xh87-mx6m-69f3 Types: Vendor Advisory
  • New CVE Received by [email protected]

    Feb. 25, 2026

    Action Type Old Value New Value
    Added Description 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.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
    Added CWE CWE-345
    Added CWE CWE-290
    Added Reference https://github.com/honojs/hono/commit/41adbf56e252c04611f8972364ac0887ae07a4c7
    Added Reference https://github.com/honojs/hono/releases/tag/v4.12.2
    Added Reference https://github.com/honojs/hono/security/advisories/GHSA-xh87-mx6m-69f3
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 8.2
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact