CVE-2026-67353

guzzlehttp/guzzle versions before 7.15.1 contain a denial of service vulnerability in the CookieJar that accepts unlimited Set-Cookie header fields with no size restrictions. Attackers can return many large cookies from a malicious server, causing Guzzle to store excessive data in memory and generate oversized Cookie headers that fail in handlers or destination servers.

guzzlehttp/guzzle versions before 7.15.1 contain a denial of service vulnerability in the CookieJar that accepts unlimited Set-Cookie header fields with no size restrictions. Attackers can return many large cookies from a malicious server, causing Guzzle to store excessive data in memory and generate oversized Cookie headers that fail in handlers or destination servers.