A flaw was found in libcurl. An application using libcurl that performs an authenticated HTTP(S) request after a Negotiate-authenticated one to the same host may incorrectly reuse the previous connection. This authentication bypass vulnerability allows the second request to be sent over a connection authenticated with different credentials, potentially leading to unauthorized access or information disclosure.

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Fixes

Solution

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Workaround

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History

Fri, 01 May 2026 01:45:00 +0000

Type Values Removed Values Added
First Time appeared Curl
Curl libcurl
Vendors & Products Curl
Curl libcurl

Fri, 01 May 2026 00:15:00 +0000

Type Values Removed Values Added
Description A flaw was found in libcurl. An application using libcurl that performs an authenticated HTTP(S) request after a Negotiate-authenticated one to the same host may incorrectly reuse the previous connection. This authentication bypass vulnerability allows the second request to be sent over a connection authenticated with different credentials, potentially leading to unauthorized access or information disclosure.
Title curl: libcurl: Authentication bypass due to incorrect HTTP Negotiate connection reuse
Weaknesses CWE-488
References
Metrics threat_severity

None

cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N'}

threat_severity

Moderate


Projects

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cve-icon MITRE

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cve-icon Vulnrichment

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cve-icon NVD

No data.

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-04-29T00:00:00Z

Links: CVE-2026-5545 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-05-01T01:30:05Z

Weaknesses