Vulnerability in Guzzle Psr7
CVE-2026-59882
guzzlehttp/psr7 is a PSR-7 HTTP message library implementation in PHP. Prior to 2.12.3, Uri::assertValidHost() does not reject URI host components containing authority delimiters, embedded ports, or malformed IPv6 brackets, allowing Uri::getHost() to disagree with the URI authority used for security or routing decisions. This issue is fixed in version 2.12.3.
EPSS: 0.002 (8.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.2 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N.
Affected products
- Guzzle Psr7 — versions < 2.12.3
- Guzzlephp Psr-7
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 (Product, x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-59882?
- CVE-2026-59882 is a medium-severity vulnerability in Guzzle Psr7, classified under CWE-436. CVSS score: 4.2/10. Published 2026-07-08.
- How severe is CVE-2026-59882?
- Medium severity. CVSS v3 base score is 4.2 out of 10.