CVE-2026-59882: CWE-436: Interpretation Conflict in guzzle psr7
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.
AI Analysis
Technical Summary
The guzzlehttp/psr7 PHP library, which implements PSR-7 HTTP message interfaces, contains a vulnerability identified as CWE-436 (Interpretation Conflict) in versions before 2.12.3. The Uri::assertValidHost() function does not properly reject host components containing authority delimiters, embedded ports, or malformed IPv6 brackets. This discrepancy allows Uri::getHost() to disagree with the URI authority used in security or routing logic, potentially causing misinterpretation of the host component. The vulnerability has a CVSS 3.1 score of 4.2 (medium severity) and was fixed in version 2.12.3.
Potential Impact
This vulnerability can lead to inconsistent interpretation of URI host components, which may cause security or routing decisions to be made based on incorrect host information. The impact is limited to confidentiality and integrity with low severity (CVSS 4.2), and no known exploits are reported in the wild.
Mitigation Recommendations
Upgrade to guzzlehttp/psr7 version 2.12.3 or later, where the Uri::assertValidHost() function properly validates URI host components to prevent interpretation conflicts. Patch status is confirmed fixed in 2.12.3. No other mitigation is indicated.
CVE-2026-59882: CWE-436: Interpretation Conflict in guzzle psr7
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.
CVSS v3.1
Score 4.2medium
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The guzzlehttp/psr7 PHP library, which implements PSR-7 HTTP message interfaces, contains a vulnerability identified as CWE-436 (Interpretation Conflict) in versions before 2.12.3. The Uri::assertValidHost() function does not properly reject host components containing authority delimiters, embedded ports, or malformed IPv6 brackets. This discrepancy allows Uri::getHost() to disagree with the URI authority used in security or routing logic, potentially causing misinterpretation of the host component. The vulnerability has a CVSS 3.1 score of 4.2 (medium severity) and was fixed in version 2.12.3.
Potential Impact
This vulnerability can lead to inconsistent interpretation of URI host components, which may cause security or routing decisions to be made based on incorrect host information. The impact is limited to confidentiality and integrity with low severity (CVSS 4.2), and no known exploits are reported in the wild.
Mitigation Recommendations
Upgrade to guzzlehttp/psr7 version 2.12.3 or later, where the Uri::assertValidHost() function properly validates URI host components to prevent interpretation conflicts. Patch status is confirmed fixed in 2.12.3. No other mitigation is indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-07-07T16:40:07.982Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4e7ad4c9d9e3dbe36a7d5d
Added to database: 07/08/2026, 16:29:08 UTC
Last enriched: 07/08/2026, 16:44:25 UTC
Last updated: 07/09/2026, 03:39:28 UTC
Views: 7
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