{"id":"GHSA-p77w-8qqv-26rm","summary":"Hono's Cache Middleware ignores Vary: Authorization / Vary: Cookie leading to cross-user cache leakage","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` — the standard signals defined in RFC 9110 / RFC 9111 to indicate per-user responses — 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`.","aliases":["CVE-2026-44457"],"modified":"2026-07-17T21:04:27.261002338Z","published":"2026-05-09T00:28:46Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2026-05-09T00:28:46Z","nvd_published_at":"2026-05-13T16:16:57Z","cwe_ids":["CWE-524"],"severity":"MODERATE"},"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"}],"affected":[{"package":{"name":"hono","ecosystem":"npm","purl":"pkg:npm/hono"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"4.12.18"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-p77w-8qqv-26rm/GHSA-p77w-8qqv-26rm.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"}]}