CVE-2026-67353 · Symaro Security Advisory

Description

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.

Severity (CVSS)

Base score	6.9
Severity	Medium
Version	CVSS 4.0
Vector	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
Provided by	CNA

Weaknesses

CWE-770 — Allocation of Resources Without Limits or Throttling

Affected products

Vendor	Product	Versions
guzzle	guzzle	0 to <7.15.1; 7.15.1

References

https://github.com/guzzle/guzzle/security/advisories/GHSA-f283-ghqc-fg79 (vendor-advisory)
https://www.vulncheck.com/advisories/guzzlehttp-guzzle-before-unbounded-cookie-denial-of-service (third-party-advisory)

Authoritative sources

This page is a snapshot. For the latest enrichment and updates, view the record on CVE.org or the NVD.

Generated from the official CVE List on 02 Aug 2026 07:05 UTC.