Bug 2521754

Summary: CVE-2026-53587 rust-tokei: libgit2: Denial of Service due to heap out-of-bounds read from malicious Git server [epel-all]
Product: [Fedora] Fedora EPEL Reporter: Vladimir Vasilev <vvasilev>
Component: rust-tokeiAssignee: Ben Beasley <code>
Status: CLOSED NOTABUG QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: epel10CC: code, decathorpe, kanru, rust-sig
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["ebcd85d7-980a-4766-b836-173bb057110d"]}
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Last Closed: 2026-08-24 09:58:12 UTC Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On:    
Bug Blocks: 2520693    

Description Vladimir Vasilev 2026-08-24 07:59:52 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, libgit2 performs a fixed-size strncmp in set_data in src/libgit2/transports/smart_pkt.c without first verifying that the smart-protocol pkt-line capability buffer contains 14 bytes. A malicious Git server can make bytes after the pkt-line complete object-format=, causing format_str to advance beyond the pkt-line and the following memchr length calculation to underflow. The resulting heap out-of-bounds walk can crash a client during the first refs-advertisement packet over HTTP, HTTPS, SSH, or the Git protocol. This issue is fixed in versions 1.8.6 and 1.9.5.
Comment 1 Ben Beasley 2026-08-24 09:58:12 UTC 
This package only uses libgit2 indirectly via the Rust git2 crate, and that only as a test dependency, so (1) I can’t see what could possibly be done here, rather than in libgit2 or rust-git2, and (2) the package can’t be affected by any vulnerabilities in a test dependency anyway.