SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAwaiting Analysis

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.

MEDIUM 6.9EPSS 0.25%

Does this matter?

Lower severity and a low EPSS score (0.25%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 4.0
6.9 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.25% probability · 16th percentile
CISA KEV
Not listed
Weakness
CWE-770
Source
disclosure@vulncheck.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.