CVE-2026-59882CWE-436

guzzlehttp/psr7: Host Confusion via Weak URI Host Validation

Medium · published July 8, 2026

CVSS v3.1
4.2
EPSS
0%
Percentile
23.4
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
4.2 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00317 · 23.4th percentile
Weakness
CWE-436 · Interpretation Conflict
Published
2026-07-08T15:50Z
EPSS history
Timeline
  • 08 JUL 15:50Z
    guzzlehttp/psr7: Host Confusion via Weak URI Host Validation
    cvelistv5