{"id":"GHSA-j6c9-x7qj-28xf","revision":"debc63023dfc41119633b39aff608d38","records":[{"revision":"debc63023dfc41119633b39aff608d38","observedAt":"2026-10-24T13:17:17.793+00:00","statement":{"source":"osv","id":"GHSA-j6c9-x7qj-28xf","aliases":["CVE-2026-54287"],"title":"hono: AWS Lambda adapter merges multiple `Set-Cookie` headers into one value, dropping cookies on ALB single-header and Lattice","description":"### Summary\n\nOn AWS Lambda, the ALB single-header response and the VPC Lattice v2 response join multiple `Set-Cookie` headers into one comma-separated value. Because commas also appear inside cookie attributes (for example `Expires` dates), clients cannot split the value back into individual cookies and silently drop or misparse them.\n\n### Details\n\nPer RFC 6265, each cookie must be its own `Set-Cookie` header line, and commas may appear inside attribute values. Joining cookies with `\", \"` collides with those commas, producing a value that clients cannot reliably split. Only ALB single-header mode and VPC Lattice v2 are affected; API Gateway v1/v2 and ALB with multi-value headers enabled already use an array and are unaffected.\n\n### Impact\n\nA client may receive only one of the cookies, a malformed cookie, or none. Session, CSRF, or preference cookies can silently fail to apply, breaking sessions or forcing re-authentication. This affects applications that set multiple cookies per response and run on AWS Lambda behind an ALB in single-header mode (the default) or VPC Lattice v2.","state":0,"publishedAt":"2026-06-16T14:08:40+00:00","modifiedAt":"2026-09-10T03:50:49.9668302+00:00","affected":[{"ecosystem":"npm","name":"hono","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"4.12.25"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"MODERATE"}],"references":["https://github.com/honojs/hono/security/advisories/GHSA-j6c9-x7qj-28xf","https://nvd.nist.gov/vuln/detail/CVE-2026-54287","https://github.com/honojs/hono"],"sourceUrl":"https://github.com/advisories/GHSA-j6c9-x7qj-28xf","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-j6c9-x7qj-28xf","identifiers":["GHSA-j6c9-x7qj-28xf","CVE-2026-54287"]},"retained":false,"historicalAffected":[]}],"coverage":[]}