Bug 2529199 (CVE-2026-19931)

Summary: CVE-2026-19931 curl: libcurl: Information disclosure via incorrect connection reuse with Negotiate authentication
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, anthomas, aos-team-art-private, asdas, bbrownin, crizzo, dpaolell, ehelms, ggainey, gtanzill, jbuscemi, jdelft, jpasqual, jupierce, juwatts, kshier, lgarciaa, mbiarnes, mdellweg, mhulan, nmoumoul, osousa, pcreech, ppalepu, ppostler, prdhamdh, rchan, rekumar, rhel-process-autobot, sdawley, sghai, sidsharm, smallamp, stcannon, suppawar, teagle, tmalecek, vlaad, vvoronko, watson-tool-maintainers, yguenane
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in libcurl. This vulnerability allows an attacker to reuse an HTTP connection set up for a given hostname using Negotiate authentication. When an initial request is made with empty credentials, a subsequent user's request can be sent over a previously authenticated connection belonging to another user. This could lead to information disclosure or unauthorized access to sensitive data.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2535994, 2535995, 2535990, 2535991, 2535992, 2535993, 2535996, 2535997, 2535998    
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Description OSIDB Bzimport 2026-09-06 17:51:20 UTC 
A flaw in libcurl makes it wrongly reuse an HTTP connection setup for a given
hostname using Negotiate authentication, when the initial request is done
using empty credentials. This can make user B's request get sent over user A's
previously authenticated connection.