What is CVE-2026-67353?

CVE-2026-67353 is a medium-severity vulnerability in Guzzle, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.3/10. Published 2026-08-01.

How severe is CVE-2026-67353?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Resource exhaustion in Guzzle

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. Attackers can return many large cookies from a malicious server…

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Affected products

Guzzle — versions 0, 7.15.1

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-67353?: CVE-2026-67353 is a medium-severity vulnerability in Guzzle, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.3/10. Published 2026-08-01.
How severe is CVE-2026-67353?: Medium severity. CVSS v3 base score is 5.3 out of 10.