Bug 2496767 (CVE-2026-11856)

Summary: CVE-2026-11856 curl: curl: Information disclosure via incorrect Digest authentication header reuse
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dbosanac, dpaolell, jdelft, jreimann, jupierce, lgarciaa, mbiarnes, mdessi, mrizzi, pcattana, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sdawley, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in curl. When `libcurl` performs a transfer to an HTTP origin using Digest authentication and then reuses the same connection handle for a subsequent transfer to a different origin, it may incorrectly send the authentication header intended for the first origin to the second. This could lead to unintended information disclosure, potentially allowing an attacker to gain unauthorized access to sensitive data.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-07-03 07:02:01 UTC 
Successfully using libcurl to do a transfer to a specific HTTP origin
(`hostA`) with **Digest** authentication and then changing the origin to a
different one (`hostB`) for a second transfer, reusing the same handle, makes
libcurl wrongly pass on the  `Authorization:` header field meant for `hostA`,
to `hostB`.