Bug 2521748

Summary: CVE-2026-53585 rust-libgit2-sys0.17: libgit2: Denial of Service via Unbounded Memory Allocation [epel-all]
Product: [Fedora] Fedora EPEL Reporter: Vladimir Vasilev <vvasilev>
Component: rust-libgit2-sys0.17Assignee: Rust SIG <rust-sig>
Status: ASSIGNED --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: epel10CC: decathorpe, rust-sig
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["7c8f2040-7633-48d0-9dfb-b8f9334a0b05"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On:    
Bug Blocks: 2520696    

Description Vladimir Vasilev 2026-08-24 07:55:47 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.

libgit2 is a portable C implementation of the Git core methods provided as a linkable library with a solid API, allowing to build Git functionality into your application. Prior to 1.8.6 and 1.9.5, git_delta_apply in src/libgit2/delta.c trusts the attacker-controlled res_sz value parsed by hdr_sz from a delta object header and passes that amount to git__malloc before validating delta instructions. Malicious pack data supplied through git_clone, git_fetch, git_remote_fetch, git_indexer_append, or a local attacker-supplied repository can use a very small multi-level OFS_DELTA chain to retain extremely large allocations and exhaust memory. This issue is fixed in versions 1.8.6 and 1.9.5.
Comment 1 Fabio Valentini 2026-08-27 12:59:52 UTC 
As far as I can tell, the only application that still (transitively) depends on rust-libgit2-sys0.17 is rust-git-absorb, and only on the f43 and epel9 branches. I have submitted pull requests to resolve this in both these branches.