{"id":"GHSA-79qm-7rj5-m7r9","revision":"3de58d4dfba84594b41d0941dcc61cb2","records":[{"revision":"3de58d4dfba84594b41d0941dcc61cb2","observedAt":"2026-10-24T13:17:17.793+00:00","statement":{"source":"osv","id":"GHSA-79qm-7rj5-m7r9","aliases":["CVE-2026-71849"],"title":"Hono: Proxy Helper does not remove response headers listed in the `Connection` header","description":"### Summary\n\nThe Proxy Helper (`hono/proxy`) does not remove response headers named by the origin's `Connection` header. Headers that the origin marked as connection-scoped are therefore forwarded to clients.\n\n### Details\n\nPer RFC 9110 Section 7.6.1, an intermediary must remove the header fields listed in a message's `Connection` header field before forwarding the message, in addition to the well-known hop-by-hop headers. The `proxy()` function removed the well-known hop-by-hop headers (including `Connection` itself) from origin responses, but did not remove the headers that the response's `Connection` header field designated as connection-scoped.\n\nThis issue arises when an application proxies responses from an origin that declares additional, non-standard headers as hop-by-hop via the `Connection` response header.\n\n### Impact\n\nA client may receive response headers that the origin intended only for its immediate peer. This may lead to:\n\n- Disclosure of connection-scoped or internal metadata contained in such headers\n\nThis issue affects applications that use the Proxy Helper (`hono/proxy`) to forward responses from origins that list custom header names in their `Connection` response header. Applications whose origins only use the standard hop-by-hop headers are not affected.","state":0,"publishedAt":"2026-08-07T18:38:48+00:00","modifiedAt":"2026-09-10T03:51:13.3173952+00:00","affected":[{"ecosystem":"npm","name":"hono","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"4.7.0"},{"kind":"fixed","version":"4.12.34"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"LOW"}],"references":["https://github.com/honojs/hono/security/advisories/GHSA-79qm-7rj5-m7r9","https://github.com/honojs/hono/commit/720b566290793d4358bf39843adcb7cf4da4548f","https://github.com/honojs/hono","https://github.com/honojs/hono/releases/tag/v4.12.34"],"sourceUrl":"https://github.com/advisories/GHSA-79qm-7rj5-m7r9","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-79qm-7rj5-m7r9","identifiers":["GHSA-79qm-7rj5-m7r9","CVE-2026-71849"]},"retained":false,"historicalAffected":[]}],"coverage":[]}