Vulnerability in Guzzle
CVE-2026-59883
Guzzle is an extensible PHP HTTP client. Prior to 7.12.3, CookieJar did not restrict cookies scoped to IP-address or bare-numeric Domain values to the exact host that set them, because SetCookie::matchesDomain() applied ordinary suffix matching to domains such as 192.168.0.1, [::1], or 1, allowing cross-host cookie disclosure, cookie injection, or session fixation. This issue is fixed in version 7.12.3.
EPSS: 0.001 (2.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N.
Affected products
- Guzzle — versions < 7.12.3
- Guzzlephp Guzzle
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Mitigation, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-59883?
- CVE-2026-59883 is a medium-severity vulnerability in Guzzle, classified under Origin Validation Error. CVSS score: 4.7/10. Published 2026-07-08.
- How severe is CVE-2026-59883?
- Medium severity. CVSS v3 base score is 4.7 out of 10.