4.2
MEDIUM CVSS 3.1
CVE-2026-59882
guzzlehttp/psr7: Host Confusion via Weak URI Host Validation
Description

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.

INFO

Published Date :

July 8, 2026, 5:17 p.m.

Last Modified :

July 10, 2026, 7:01 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-59882 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Guzzlephp psr-7
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 MEDIUM [email protected]
Solution
Update guzzlehttp/psr7 to version 2.12.3 or later to fix host validation.
  • Update the guzzlehttp/psr7 library to version 2.12.3 or later.
  • Validate URI host components after the update.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-59882.

URL Resource
https://github.com/guzzle/psr7/commit/ddd64f17d4cc1f7e5ffe6fd2c989ec7221712580
https://github.com/guzzle/psr7/pull/811
https://github.com/guzzle/psr7/releases/tag/2.12.3
https://github.com/guzzle/psr7/security/advisories/GHSA-c2w2-prh8-qm98
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-59882 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-59882 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-59882 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-59882 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 08, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-59882', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-08T16:50:26.023312Z'}
  • New CVE Received by [email protected]

    Jul. 08, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'guzzle', 'product': 'psr7', 'versions': [{'status': 'affected', 'version': '< 2.12.3'}]}]
    Added Description 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.
    Added CVSS V3.1 AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N
    Added CWE CWE-436
    Added Reference https://github.com/guzzle/psr7/commit/ddd64f17d4cc1f7e5ffe6fd2c989ec7221712580
    Added Reference https://github.com/guzzle/psr7/pull/811
    Added Reference https://github.com/guzzle/psr7/releases/tag/2.12.3
    Added Reference https://github.com/guzzle/psr7/security/advisories/GHSA-c2w2-prh8-qm98
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.