GHSA-WFC6-R584-VFW7
Vulnerability from github – Published: 2026-05-11 15:54 – Updated: 2026-05-14 20:38Impact
Applications using React Server Components can be vulnerable to cache poisoning when shared caches do not correctly partition response variants. Under affected conditions, an attacker can cause an RSC response to be served from the original URL and poison shared cache entries so later visitors receive component payloads instead of the expected HTML.
Fix
We now validate and interpret RSC request headers consistently across request classification and rendering, and we enforce the intended cache-busting behavior so RSC payloads are not unexpectedly served from the original URL.
Workarounds
If you cannot upgrade immediately, ensure your CDN or reverse proxy keys on the relevant RSC request headers and honors Vary, or disable shared caching for affected App Router and RSC responses.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "next"
},
"ranges": [
{
"events": [
{
"introduced": "14.2.0"
},
{
"fixed": "15.5.16"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "next"
},
"ranges": [
{
"events": [
{
"introduced": "16.0.0"
},
{
"fixed": "16.2.5"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-44576"
],
"database_specific": {
"cwe_ids": [
"CWE-436"
],
"github_reviewed": true,
"github_reviewed_at": "2026-05-11T15:54:46Z",
"nvd_published_at": "2026-05-13T17:16:23Z",
"severity": "MODERATE"
},
"details": "### Impact\n\nApplications using React Server Components can be vulnerable to cache poisoning when shared caches do not correctly partition response variants. Under affected conditions, an attacker can cause an RSC response to be served from the original URL and poison shared cache entries so later visitors receive component payloads instead of the expected HTML.\n\n### Fix\n\nWe now validate and interpret `RSC` request headers consistently across request classification and rendering, and we enforce the intended cache-busting behavior so RSC payloads are not unexpectedly served from the original URL.\n\n### Workarounds\n\nIf you cannot upgrade immediately, ensure your CDN or reverse proxy keys on the relevant RSC request headers and honors `Vary`, or disable shared caching for affected App Router and RSC responses.",
"id": "GHSA-wfc6-r584-vfw7",
"modified": "2026-05-14T20:38:11Z",
"published": "2026-05-11T15:54:46Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/vercel/next.js/security/advisories/GHSA-wfc6-r584-vfw7"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-44576"
},
{
"type": "PACKAGE",
"url": "https://github.com/vercel/next.js"
},
{
"type": "WEB",
"url": "https://github.com/vercel/next.js/releases/tag/v15.5.16"
},
{
"type": "WEB",
"url": "https://github.com/vercel/next.js/releases/tag/v16.2.5"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:L",
"type": "CVSS_V3"
}
],
"summary": "Next.js vulnerable to cache poisoning in React Server Component responses"
}
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.