GHSA-J9V4-RHGR-4M5F
Vulnerability from github – Published: 2026-09-17 14:52 – Updated: 2026-09-17 14:52Summary
A flaw in the CORS plugin allowed the incoming request's Vary header to be reflected into the response, letting a client influence a header that should be controlled solely by the server.
Details
The CORS plugin previously copied the request's Vary header directly onto the response instead of treating Vary as a response-only header. Because Vary tells downstream caches and proxies how to key their cached responses, this allowed a client to inject arbitrary values into the response's Vary header, potentially distorting cache-key behavior in shared caches/CDNs sitting in front of an oRPC server and leading to inconsistent CORS enforcement for other clients.
Practical impact is limited to deployments where a shared cache or reverse proxy keys on the Vary header; the real-world effect depends on the caching layer's configuration.
Impact
May cause cache key pollution and inconsistent CORS enforcement in setups that rely on shared/edge caches keying on Vary. No direct confidentiality, integrity, or availability impact in default (non-cached) configurations.
Resolution
Update @orpc/server (and any other @orpc/* packages bundling the CORS plugin) to 1.14.8. The CORS plugin now derives Vary exclusively from the response, appending Origin and preserving existing values instead of reflecting request headers.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 1.14.7"
},
"package": {
"ecosystem": "npm",
"name": "@orpc/server"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.14.8"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-77360"
],
"database_specific": {
"cwe_ids": [
"CWE-113"
],
"github_reviewed": true,
"github_reviewed_at": "2026-09-17T14:52:37Z",
"nvd_published_at": "2026-09-16T19:17:38Z",
"severity": "MODERATE"
},
"details": "### Summary\nA flaw in the CORS plugin allowed the incoming request\u0027s `Vary` header to be reflected into the response, letting a client influence a header that should be controlled solely by the server.\n\n### Details\nThe CORS plugin previously copied the request\u0027s `Vary` header directly onto the response instead of treating `Vary` as a response-only header. Because `Vary` tells downstream caches and proxies how to key their cached responses, this allowed a client to inject arbitrary values into the response\u0027s `Vary` header, potentially distorting cache-key behavior in shared caches/CDNs sitting in front of an oRPC server and leading to inconsistent CORS enforcement for other clients.\n\nPractical impact is limited to deployments where a shared cache or reverse proxy keys on the `Vary` header; the real-world effect depends on the caching layer\u0027s configuration.\n\n### Impact\nMay cause cache key pollution and inconsistent CORS enforcement in setups that rely on shared/edge caches keying on `Vary`. No direct confidentiality, integrity, or availability impact in default (non-cached) configurations.\n\n### Resolution\nUpdate `@orpc/server` (and any other `@orpc/*` packages bundling the CORS plugin) to `1.14.8`. The CORS plugin now derives `Vary` exclusively from the response, appending `Origin` and preserving existing values instead of reflecting request headers.",
"id": "GHSA-j9v4-rhgr-4m5f",
"modified": "2026-09-17T14:52:38Z",
"published": "2026-09-17T14:52:37Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/middleapi/orpc/security/advisories/GHSA-j9v4-rhgr-4m5f"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-77360"
},
{
"type": "WEB",
"url": "https://github.com/middleapi/orpc/issues/1661"
},
{
"type": "WEB",
"url": "https://github.com/middleapi/orpc/pull/1662"
},
{
"type": "WEB",
"url": "https://github.com/middleapi/orpc/commit/daabded122a89d323357c4c401e879701864cb2f"
},
{
"type": "PACKAGE",
"url": "https://github.com/middleapi/orpc"
},
{
"type": "WEB",
"url": "https://github.com/middleapi/orpc/releases/tag/v1.14.8"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
"type": "CVSS_V4"
}
],
"summary": "oRPC: Vary Header Injection in CORS Plugin leading to potential Cache/CORS Bypass"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
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