Bug 2559371 (CVE-2026-115374)

Summary: CVE-2026-115374 github.com/lxc/incus: incus: Information disclosure via unsigned headers in presigned S3 URLs
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: high    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Incus. The built-in Simple Storage Service (S3) server does not properly verify request signatures, allowing an attacker with a presigned upload URL to inject unsigned request headers. By supplying an unauthorized copy source header, an attacker can copy other storage bucket objects to an accessible destination key, leading to unauthorized information disclosure.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2560124    
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Description OSIDB Bzimport 2026-10-22 20:54:47 UTC 
Incus 7.0.0 before 7.0.2 and 7.1.0 before 7.5.0 contains a signature verification flaw in its built-in S3 server that allows presigned URL holders to inject unsigned x-amz-* headers. Attackers can add an unsigned X-Amz-Copy-Source header to a presigned upload URL to copy other bucket objects onto the granted key, disclosing their contents and ETags.