CVE-2026-67353

MEDIUM 5.3

guzzlehttp/guzzle before 7.15.1 Unbounded Cookie Denial of Service

CVSS Score

5.3

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-770
Vendor	guzzle
Product	guzzle
Published	Aug 1, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

Low

Affected Versions

guzzle / guzzle

0 < 7.15.1

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/guzzle/guzzle/security/advisories/GHSA-f283-ghqc-fg79 vulncheck.com: https://www.vulncheck.com/advisories/guzzlehttp-guzzle-before-unbounded-cookie-denial-of-service

Credits

🔍 GrahamCampbell