Bug 2567908 (CVE-2026-109518)

Summary: CVE-2026-109518 apt: apt: Remote code execution via hard link reuse during package download retries
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 APT. This vulnerability allows an on-path network attacker to achieve arbitrary code execution with administrative (root) privileges by intercepting package downloads. By manipulating network traffic when a client follows redirects and retries a download, an attacker can exploit insecure hard link reuse to force the installation of an unverified, malicious package.
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Description OSIDB Bzimport 2026-11-05 22:35:31 UTC 
On Debian, Ubuntu, and derivative Linux distributions, an on-path attacker who can manipulate the HTTP traffic (including a malicious mirror or proxy) between an APT client and an archive server triggered by a package install can trick the client into installing an attacker-controlled unverified package and achieve remote code execution with root privileges.



The vulnerability is caused by the reuse of hard links and requires the client to follow redirects and retry the download of package files. It requires the client to have a non-zero Acquire::Retries configuration setting; the value 3 is the default starting with Debian 12 (bookworm) and Ubuntu 22.04 LTS (Jammy Jellyfish), so older releases are unaffected in a default configuration