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.

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 mat…

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

Weakness classification (CWE)

CWE-346 — Origin Validation Error
CWE-384 — Session Fixation

References

security-advisories@github.com (x_refsource_CONFIRM)
security-advisories@github.com (x_refsource_MISC)
security-advisories@github.com (x_refsource_MISC)
security-advisories@github.com (x_refsource_MISC)

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.