CVE-2026-80230

Modified Modified - Updated After Analysis

libcurl Public Key Pinning Bypass with Disabled Verification

Publication date: 2026-09-06

Last updated on: 2026-09-15

Assigner: curl

Description

When `CURLOPT_PINNEDPUBLICKEY` is configured alongside options that disable standard peer verification (`CURLOPT_SSL_VERIFYPEER = 0` and `CURLOPT_SSL_VERIFYHOST = 0`), libcurl fails to enforce public key pinning on connections established without a presented server certificate. Bypassing the pinning check under these disabled-verification conditions allows unauthenticated connections to succeed when they should be rejected.

CVSS Scores

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Meta Information

Published

2026-09-06

Last Modified

2026-09-15

Generated

2026-09-28

AI Q&A

2026-09-06

EPSS Evaluated

2026-09-26

NVD

CVE-2026-80230

EUVD

EUVD-2026-72168

Affected Vendors & Products

Vendor	Product	Version / Range
haxx	curl	From 7.45.0 (inc) to 8.22.0 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-295	The product does not validate, or incorrectly validates, a certificate.

Attack-Flow Graph

Executive Summary

CVE-2026-80230 is a vulnerability in curl versions 7.45.0 through 8.21.0 where public key pinning is bypassed when standard peer verification is disabled. If CURLOPT_PINNEDPUBLICKEY is set alongside CURLOPT_SSL_VERIFYPEER=0 and CURLOPT_SSL_VERIFYHOST=0, libcurl fails to enforce pinning on connections without a server certificate. This allows unauthenticated connections to succeed when they should be rejected.

Detection Guidance

Check curl version with 'curl --version' to see if it falls within vulnerable range 7.45.0 to 8.21.0. Inspect applications using libcurl for CURLOPT_PINNEDPUBLICKEY combined with CURLOPT_SSL_VERIFYPEER=0 and CURLOPT_SSL_VERIFYHOST=0.

Impact Analysis

This vulnerability could allow attackers to bypass security checks and establish unauthorized connections to vulnerable systems. If an application uses curl with disabled peer verification and public key pinning, it may connect to malicious servers impersonating trusted ones, leading to data breaches or unauthorized access.

Compliance Impact

This vulnerability may violate compliance requirements that mandate secure communication and proper certificate validation, such as GDPR's data protection principles or HIPAA's security rules. Failure to enforce public key pinning could result in unauthorized data transmission, potentially leading to non-compliance and regulatory penalties.

Mitigation Strategies

Upgrade curl to version 8.22.0 or later. If upgrading is not possible, remove configurations that disable peer verification (CURLOPT_SSL_VERIFYPEER=0 and CURLOPT_SSL_VERIFYHOST=0) or disable CURLOPT_PINNEDPUBLICKEY until patched.

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