Flaw in libcurl Allows Improper HTTPS Connection Reuse
CVE-2026-80231

7.5HIGH

Key Information:

Vendor

Curl

Status
Curl
Vendor
CVE Published:
6 September 2026

What is CVE-2026-80231?

A flaw in libcurl results in the incorrect reuse of an existing HTTPS connection associated with a specific hostname. This occurs even when using a different Native CA Store setting (CURLSSLOPT_NATIVE_CA) from that of the original connection establishment. As a result, this vulnerability may expose systems to potential security risks by enabling the misuse of trusted connections under varied CA configurations.

Affected Version(s)

curl 7.71.0 < 8.14.2

curl 8.15.0 < 8.16.1

curl 8.17.0 < 8.20.1

References

https://curl.se/docs/CVE-2026-80231.json
https://curl.se/docs/CVE-2026-80231.html
https://hackerone.com/reports/3969368

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Stanislav Fort (Aisle Research)
Daniel Stenberg
.