---
id: CVE-2026-67353
title: >-
  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
summary: >-
  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 serve…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-770
published: '2026-08-01'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T20:35:01.260'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-67353'
references:
  - url: 'https://github.com/guzzle/guzzle/security/advisories/GHSA-f283-ghqc-fg79'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/guzzlehttp-guzzle-before-unbounded-cookie-denial-of-service
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.00418
epssPercentile: 0.33365
ingestedAt: '2026-08-02T09:18:11.766Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.