{"id":"CVE-2026-54290","aliases":["GHSA-88fw-hqm2-52qc"],"url":"https://o3.security/vulnerability/CVE-2026-54290","summary":"Hono: CORS Middleware reflects any Origin with credentials when `origin` defaults to the wildcard","details":"### Summary\n\nWith `credentials: true` and no explicit `origin` (the default wildcard), the CORS Middleware reflects the request's `Origin` and sends `Access-Control-Allow-Credentials: true`. Any site can then make credentialed cross-origin requests and read the responses, exposing cookie-authenticated endpoints to arbitrary origins.\n\n### Details\n\nThe spec forbids `Access-Control-Allow-Origin: *` with credentials and browsers reject it, so this configuration used to fail closed. In affected versions the middleware reflects the request `Origin` instead, so it now succeeds for every origin, including `null`. The preflight also echoes the requested headers back, approving non-simple credentialed requests too.\n\nThis issue arises when an application enables `credentials: true` and leaves `origin` unset or set to the wildcard.\n\n### Impact\n\nAny third-party page a logged-in user visits can read the application's cookie-authenticated endpoints and perform credentialed state-changing requests. This affects applications that enable credentialed CORS without restricting `origin`.","published":"2026-06-22T17:15:35.689Z","modified":"2026-08-12T03:51:26.838246248Z","cvss":{"score":7.1,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N"},"epss":{"score":0.00328,"percentile":0.26003,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"hono","fixedVersion":"4.12.25"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54290.json"},{"type":"ADVISORY","url":"https://github.com/honojs/hono/security/advisories/GHSA-88fw-hqm2-52qc"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-54290"},{"type":"PACKAGE","url":"https://github.com/honojs/hono"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:26.838246248Z"}}