certificate option, so a cached, already authenticated Schannel connection can
be handed to a transfer that got redirected to a different origin, even though
the code explicitly switched off the auto client cert option for that transfer
to prevent exactly this.
Analysis and contextual insights are available on OpenCVE Cloud.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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Tue, 20 Oct 2026 20:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | A flaw was found in curl. In builds configured with the Microsoft Schannel Transport Layer Security (TLS) backend, libcurl's connection cache fails to evaluate client certificate authentication settings when handling HTTP redirects. A malicious server can redirect a transfer to a different destination, causing curl to inappropriately reuse an already authenticated connection. This issue can result in information disclosure by exposing client certificates and credentials to unintended origins. | libcurl's connection cache match function never considers the automatic client certificate option, so a cached, already authenticated Schannel connection can be handed to a transfer that got redirected to a different origin, even though the code explicitly switched off the auto client cert option for that transfer to prevent exactly this. |
| Title | curl: curl: auto client cert connection reuse mixup | auto client cert connection reuse mixup |
| References |
|
Sun, 18 Oct 2026 14:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Curl
Curl curl |
|
| Vendors & Products |
Curl
Curl curl |
Sat, 17 Oct 2026 00:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | A flaw was found in curl. In builds configured with the Microsoft Schannel Transport Layer Security (TLS) backend, libcurl's connection cache fails to evaluate client certificate authentication settings when handling HTTP redirects. A malicious server can redirect a transfer to a different destination, causing curl to inappropriately reuse an already authenticated connection. This issue can result in information disclosure by exposing client certificates and credentials to unintended origins. | |
| Title | curl: curl: auto client cert connection reuse mixup | |
| Weaknesses | CWE-201 | |
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Status: PUBLISHED
Assigner: curl
Published:
Updated: 2026-10-20T20:08:29.941Z
Reserved: 2026-09-07T12:11:55.106Z
Link: CVE-2026-86415
No data.
Status : Received
Published: 2026-10-20T21:17:20.067
Modified: 2026-10-20T21:17:20.067
Link: CVE-2026-86415
OpenCVE Enrichment
Updated: 2026-10-20T23:00:23Z