GHSA-WGPF-JWQJ-8H8P
Vulnerability from github – Published: 2026-06-16 14:32 – Updated: 2026-06-16 14:32Summary
On AWS Lambda@Edge, CloudFront delivers a request header that appears more than once as several separate entries. The adapter writes each value with Headers.set instead of Headers.append, so every value overwrites the previous one and only the last reaches the application. Repeated request headers such as X-Forwarded-For, Forwarded, and Via are silently truncated to a single value.
Details
A repeated request header carries an ordered list of values. The adapter iterates the list but overwrites on each step, keeping only the final value. Middleware that depends on the full list — for example IP restriction that walks the X-Forwarded-For chain, or auditing based on Forwarded/Via hops — receives incomplete data. The API Gateway adapter already appends repeated values and is not affected.
This issue arises only on Lambda@Edge deployments, for requests that contain the same header more than once.
Impact
Request middleware sees only the last value of a repeated header instead of the full chain. For applications that base access control on the X-Forwarded-For chain, this can weaken or alter that decision; for auditing, hop history is lost. This affects applications deployed on AWS Lambda@Edge that rely on multi-value request headers.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "hono"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.12.25"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-54289"
],
"database_specific": {
"cwe_ids": [
"CWE-348"
],
"github_reviewed": true,
"github_reviewed_at": "2026-06-16T14:32:31Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "### Summary\n\nOn AWS Lambda@Edge, CloudFront delivers a request header that appears more than once as several separate entries. The adapter writes each value with `Headers.set` instead of `Headers.append`, so every value overwrites the previous one and only the last reaches the application. Repeated request headers such as `X-Forwarded-For`, `Forwarded`, and `Via` are silently truncated to a single value.\n\n### Details\n\nA repeated request header carries an ordered list of values. The adapter iterates the list but overwrites on each step, keeping only the final value. Middleware that depends on the full list \u2014 for example IP restriction that walks the `X-Forwarded-For` chain, or auditing based on `Forwarded`/`Via` hops \u2014 receives incomplete data. The API Gateway adapter already appends repeated values and is not affected.\n\nThis issue arises only on Lambda@Edge deployments, for requests that contain the same header more than once.\n\n### Impact\n\nRequest middleware sees only the last value of a repeated header instead of the full chain. For applications that base access control on the `X-Forwarded-For` chain, this can weaken or alter that decision; for auditing, hop history is lost. This affects applications deployed on AWS Lambda@Edge that rely on multi-value request headers.",
"id": "GHSA-wgpf-jwqj-8h8p",
"modified": "2026-06-16T14:32:31Z",
"published": "2026-06-16T14:32:31Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/honojs/hono/security/advisories/GHSA-wgpf-jwqj-8h8p"
},
{
"type": "PACKAGE",
"url": "https://github.com/honojs/hono"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N",
"type": "CVSS_V3"
}
],
"summary": "hono: Lambda@Edge adapter keeps only the last value of a repeated request header, dropping the rest"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.