CVE-2026-109518
HighCVSS 7.7Exploitation Probability (EPSS)
Elevated risk61th percentile - higher than 61% of all known CVEs
Summary
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.
Risk Assessment
An on-path network attacker can cause installation of a malicious package with root privileges, taking full control of the system.
Recommendation
Update APT to a version containing the fix. Consider setting Acquire::Retries=0 or using secure package sources (HTTPS) until updated.
Other vulnerabilities in APT
See all- CVE-2014-0489High
APT versions before 1.0.9, when the Acquire::GzipIndexes option is enabled, do not validate checksums, allowing remote attackers to execute arbitrary code via a crafted package.
- CVE-2014-0487High
APT versions before 1.0.9 do not verify downloaded files if they have been modified as indicated by the If-Modified-Since header. This can lead to unspecified impacts and attack vectors.
Original NVD description (English source)
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
Vulnerability data from NVD (NIST) · CISA KEV · EPSS