GHSA-P77W-8QQV-26RM

Vulnerability from github – Published: 2026-05-09 00:28 – Updated: 2026-05-14 20:35
VLAI
Summary
Hono's Cache Middleware ignores Vary: Authorization / Vary: Cookie leading to cross-user cache leakage
Details

Summary

Cache Middleware does not skip caching for responses that declare per-user variance via Vary: Authorization or Vary: Cookie. As a result, a response cached for one authenticated user may be served to subsequent requests from different users.

Details

The Cache Middleware skips caching when a response carries Vary: *, certain Cache-Control directives (private, no-store, no-cache), or Set-Cookie. However, Vary: Authorization and Vary: Cookie — the standard signals defined in RFC 9110 / RFC 9111 to indicate per-user responses — are not treated as cache-skip reasons.

This issue arises when applications use the Cache Middleware on endpoints that return user-specific data and rely on Vary: Authorization or Vary: Cookie to scope the response per user, without also setting Cache-Control: private.

Impact

A user may receive a cached response that was originally generated for a different authenticated user. This may lead to:

  • Disclosure of personally identifiable information or other user-specific data present in the response body
  • Inconsistent or incorrect behavior in user-specific endpoints

This issue affects applications that use the Cache Middleware on endpoints whose responses vary by Authorization or Cookie and that do not also set Cache-Control: private.

Severity
5.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "hono"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.12.18"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-44457"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-524"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-09T00:28:46Z",
    "nvd_published_at": "2026-05-13T16:16:57Z",
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nCache Middleware does not skip caching for responses that declare per-user variance via `Vary: Authorization` or `Vary: Cookie`. As a result, a response cached for one authenticated user may be served to subsequent requests from different users.\n\n### Details\n\nThe Cache Middleware skips caching when a response carries `Vary: *`, certain `Cache-Control` directives (`private`, `no-store`, `no-cache`), or `Set-Cookie`. However, `Vary: Authorization` and `Vary: Cookie` \u2014 the standard signals defined in RFC 9110 / RFC 9111 to indicate per-user responses \u2014 are not treated as cache-skip reasons.\n\nThis issue arises when applications use the Cache Middleware on endpoints that return user-specific data and rely on `Vary: Authorization` or `Vary: Cookie` to scope the response per user, without also setting `Cache-Control: private`.\n\n### Impact\n\nA user may receive a cached response that was originally generated for a different authenticated user. This may lead to:\n\n- Disclosure of personally identifiable information or other user-specific data present in the response body\n- Inconsistent or incorrect behavior in user-specific endpoints\n\nThis issue affects applications that use the Cache Middleware on endpoints whose responses vary by `Authorization` or `Cookie` and that do not also set `Cache-Control: private`.",
  "id": "GHSA-p77w-8qqv-26rm",
  "modified": "2026-05-14T20:35:40Z",
  "published": "2026-05-09T00:28:46Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/honojs/hono/security/advisories/GHSA-p77w-8qqv-26rm"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-44457"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/honojs/hono"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Hono\u0027s Cache Middleware ignores Vary: Authorization / Vary: Cookie leading to cross-user cache leakage"
}



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