CVE-2026-54287

Summary: Hono’s AWS Lambda adapter, in the ALB single-header mode and VPC Lattice v2, concatenates multiple Set-Cookie headers into a single comma-separated value, causing cookie attributes that include commas (e.g., Expires) to be misparsed or dropped. Affected components: Hono web framework; AW...

CVE-2026-54287 Hono: AWS Lambda adapter merges multiple `Set-Cookie` headers into one value, dropping cookies on ALB single-header and Lattice

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.25, 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 attribute...