Hono is Vulnerable to Authentication Bypass by IP Spoofing in AWS Lambda ALB conninfo
Exploitation and risk
Source statusCISA KEV lists vulnerabilities known to be exploited. FIRST EPSS estimates the likelihood of exploitation in the next 30 days. An unavailable score does not mean zero risk.
Which CVEs have scores here?
This view includes predictions for CVE identifiers explicitly listed in public NuGet advisories. Microsoft release pages have their own prediction coverage. Check source status for the scope and latest checks.
No exploitation or prediction data is available here for these CVEs. This does not mean they are safe or unlikely to be exploited.
cve-program · CVE-2026-27700
PublishedHono 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.
- Source published
- 25 Feb 2026 15:01:44 UTC
- Source modified
- 27 Feb 2026 17:01:28 UTC
- Saved here
- 23 Oct 2026 15:48:27 UTC
- Source terms
- CVE Program Terms of Use
Original source record · Cite this exact observation · Complete original publisher JSON
Source: cve-program · CVE Program Terms of Use. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS 3.1 · 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
euvd · EUVD-2026-8644
PublishedHono 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.
Additional publisher context
EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.
Original publisher date fields
datePublished: Feb 25, 2026, 3:01:44 PM
dateUpdated: Feb 27, 2026, 5:01:28 PM
- Source published
- Feb 25, 2026, 3:01:44 PM (timezone not stated)
- Source modified
- Feb 27, 2026, 5:01:28 PM (timezone not stated)
- Saved here
- 15 Nov 2026 11:08:33 UTC
- Source terms
- ENISA EUVD · source terms and attribution apply
Original source record · Cite this exact observation · Complete original publisher JSON
Source: euvd · ENISA EUVD · source terms and attribution apply. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
EUVD CVSS 3.1 · 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
nvd · CVE-2026-27700
PublishedHono 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.
Additional publisher context
NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.
Source analysis status: Analyzed
Weakness classifications: CWE-290 · CWE-345
Original publisher date fields
published: 2026-02-25T16:23:26.440
lastModified: 2026-06-17T10:27:32.397
1 source CPE criteria · context only
- cpe:2.3:a:hono:hono:*:*:*:*:*:node.js:*:*
The original JSON retains the logical configuration operators, exclusions and version bounds.
- Source published
- 25 Feb 2026 16:23:26 UTC
- Source modified
- 17 Jun 2026 10:27:32 UTC
- Saved here
- 25 Oct 2026 06:17:33 UTC
- Source terms
- NIST NVD usage terms; underlying source attribution retained
Original source record · Cite this exact observation · Complete original publisher JSON
Source: nvd · NIST NVD usage terms; underlying source attribution retained. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS 3.1 · [email protected] · Secondary · 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
CVSS 3.1 · [email protected] · Primary · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
osv · GHSA-xh87-mx6m-69f3
Published## Summary 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. ## Details In ALB environments, AWS appends the actual client IP address to the end of any existing `X-Forwarded-For` header value. However, the previous implementation of `getConnInfo()` extracted the leftmost IP address: ```ts address = xff.split(',')[0].trim() ``` If a client sent: ``` X-Forwarded-For: <spoofed-ip> ``` ALB would forward: ``` X-Forwarded-For: <spoofed-ip>, <real-client-ip> ``` Since the implementation selected the first value, the spoofed IP address was trusted. This affected applications using: ```ts ipRestriction(getConnInfo, { allowList: [...] }) ``` or any custom middleware relying on `getConnInfo(c).remote.address` for authorization decisions. The issue only affects deployments using the AWS Lambda adapter behind an ALB. API Gateway (v1/v2) and Lambda Function URLs are not affected, as they use AWS-provided source IP values from `requestContext`. ## Impact An unauthenticated remote attacker could bypass IP-based access restrictions by supplying a crafted `X-Forwarded-For` header. This may allow access to resources that were intended to be restricted by IP address. Only applications deployed behind an ALB and relying on `getConnInfo()` for IP-based authorization are affected.
- Source published
- 25 Feb 2026 18:02:19 UTC
- Source modified
- 10 Sep 2026 03:50:36 UTC
- Saved here
- 24 Oct 2026 13:17:17 UTC
- Source terms
- GitHub Advisory Database · CC-BY-4.0
Original source record · Cite this exact observation · Complete original publisher JSON
Source: osv · GitHub Advisory Database · CC-BY-4.0. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
Publisher rating · HIGH