GHSA-j6c9-x7qj-28xf
Dashboard / Vulnerabilities / GHSA-j6c9-x7qj-28xf
Summary: hono: AWS Lambda adapter merges multiple `Set-Cookie` headers into one value, dropping cookies on ALB single-header and Lattice
Details: ### Summary On 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. ### Details Per 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. ### Impact A 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.
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
Affected packages
Package
Name: hono
Purl: pkg:npm/hono
Affected ranges
Type: SEMVER
Events:
