Bug 2520149

Summary: CVE-2026-77014 libsoup: libsoup: Integer truncation in sort_ranges() comparator causes silent omission of HTTP Range responses [fedora-all]
Product: [Fedora] Fedora Reporter: Thibault Guittet <tguittet>
Component: libsoupAssignee: Gwyn Ciesla <gwync>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: gwync, mclasen, rhughes, rstrode, tpopela
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["45ee20ae-6ef3-4ecd-8241-4f58a99336fb"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On:    
Bug Blocks: 2520143    

Description Thibault Guittet 2026-08-20 07:59:16 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

A flaw was found in libsoup's SoupServer HTTP Range header processing. The sort_ranges() comparator function in soup-message-headers.c returns the difference of two goffset (64-bit) values as an int (32-bit). When two range start positions in a multi-range request differ by more than INT_MAX (~2.1 billion), the truncation flips the comparison result sign, violating qsort's ordering contract. The mis-sorted ranges are then incorrectly merged, causing the server to silently omit requested byte ranges from the HTTP 206 Partial Content response. A remote unauthenticated attacker can trigger this by sending a multi-range Range request for a resource larger than approximately 2 GB, with range start offsets more than INT_MAX apart. The client receives fewer ranges than requested with no error indication, compromising data integrity for resumable downloads, delta updates, mirror synchronization, and chunked verification of large objects.