CVE-2026-80231
Received Received - Intake

libcurl HTTPS Connection Reuse with Native CA Store Misconfiguration

Vulnerability report for CVE-2026-80231, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-09-06

Last updated on: 2026-09-06

Assigner: curl

Description

A flaw in libcurl makes it wrongly reuse an existing HTTPS connection setup for a given hostname even when using a different Native CA Store setting (`CURLSSLOPT_NATIVE_CA`) than when the connection was created.

CVSS Scores

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Meta Information

Published
2026-09-06
Last Modified
2026-09-06
Generated
2026-09-08
AI Q&A
2026-09-06
EPSS Evaluated
N/A
NVD
EUVD

Affected Vendors & Products

Showing 5 associated CPEs
Vendor Product Version / Range
curl libcurl From 7.71.0 (inc) to 8.21.0 (inc)
curl libcurl 8.22.0
curl curl From 7.71.0 (inc) to 8.21.0 (inc)
curl curl 8.22.0
curl libcurl *

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in libcurl causes it to reuse an existing HTTPS connection for a hostname even when the Native CA Store setting differs from when the connection was created. This only affects Windows and macOS and impacts the curl command line tool. It was introduced in curl 7.71.0 and fixed in 8.22.0.

Detection Guidance

To detect this vulnerability, check the version of curl/libcurl installed on your system. Run 'curl --version' to see if it falls within the affected range (7.71.0 to 8.21.0). If so, the system is potentially vulnerable.

Impact Analysis

This flaw could expose data to the wrong session due to improper handling of CA store configurations. It may lead to security risks if sensitive data is transmitted over an unintended connection. Users should upgrade to curl 8.22.0 or apply a patch to mitigate the issue.

Compliance Impact

This vulnerability could potentially lead to data exposure by reusing HTTPS connections with incorrect CA store settings, which may violate data protection requirements under GDPR or HIPAA if sensitive data is transmitted insecurely.

Mitigation Strategies

Upgrade curl to version 8.22.0 or later. Alternatively, apply a patch or enable CURLOPT_FORBID_REUSE for transfers using the native CA store.

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