libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse if one of them matches the setup. (CVE-2026-11564)
libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse if one of them matches the setup. An easy handle that first uses default native CA trust can continue trusting the native platform store after the application switches that same handle to custom CA material for a later transfer.
AI Analysis
Technical Summary
libcurl maintains a connection pool to reuse connections for subsequent transfers if they match the setup. However, when an easy handle first uses the default native CA trust store and later switches to custom CA material, it may continue trusting the native platform's CA store due to connection reuse. This can cause the handle to accept certificates trusted by the native store despite the application's intent to use a different trust configuration.
Potential Impact
The vulnerability may cause libcurl to trust certificates from the native platform CA store even when the application has switched to custom CA certificates. This could lead to unintended trust of TLS connections, potentially undermining the application's security policy regarding certificate validation.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, avoid reusing easy handles across transfers with different CA trust configurations or explicitly close and recreate handles when changing CA material.
libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse if one of them matches the setup. (CVE-2026-11564)
Description
libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse if one of them matches the setup. An easy handle that first uses default native CA trust can continue trusting the native platform store after the application switches that same handle to custom CA material for a later transfer.
CVSS v3.1
Score 9.1critical
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
libcurl maintains a connection pool to reuse connections for subsequent transfers if they match the setup. However, when an easy handle first uses the default native CA trust store and later switches to custom CA material, it may continue trusting the native platform's CA store due to connection reuse. This can cause the handle to accept certificates trusted by the native store despite the application's intent to use a different trust configuration.
Potential Impact
The vulnerability may cause libcurl to trust certificates from the native platform CA store even when the application has switched to custom CA certificates. This could lead to unintended trust of TLS connections, potentially undermining the application's security policy regarding certificate validation.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, avoid reusing easy handles across transfers with different CA trust configurations or explicitly close and recreate handles when changing CA material.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-hf82-6jff-f22v
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-11564"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- 3.1
Threat ID: 6a483cb627e9c79719d8210e
Added to database: 07/03/2026, 22:50:30 UTC
Last enriched: 07/03/2026, 23:03:46 UTC
Last updated: 07/31/2026, 19:22:57 UTC
Views: 53
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