Bug 2510040 (CVE-2026-67353)

Summary: CVE-2026-67353 guzzlehttp/guzzle: guzzlehttp/guzzle: Denial of Service via unbounded cookie storage
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedKeywords: Security
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in guzzlehttp/guzzle. A remote attacker can exploit this vulnerability by sending an excessive number of large 'Set-Cookie' header fields from a malicious server. This causes the application's CookieJar to store an unbounded amount of data in memory, leading to resource exhaustion. The consequence is a Denial of Service (DoS), where the application becomes unresponsive or crashes due to excessive memory consumption and oversized cookie headers.
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-08-01 13:04:45 UTC
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.