Is there a public exploit for CVE-2026-109518?

Yes. Proof-of-concept code for CVE-2026-109518 has been published publicly.

Is there a proof of concept for CVE-2026-109518?

Yes — 3 proof-of-concept entries are linked on this page, from public repositories and community submissions. They are listed for authorised testing only.

How severe is CVE-2026-109518?

CVE-2026-109518 scores CVSS 7.7 (v4.0), rated high.

What does CVE-2026-109518 affect?

CVE-2026-109518 affects Ubuntu, Debian apt.

7.7 High

On Debian, Ubuntu, and derivative Linux distributions, an on-path attacker who can manipulate the HTTP traffic (including a malicious…

CVE-2026-109518

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

Proof-of-concept code is published

Public PoC

Public PoCjordanhardee/cve-2026-109518-apt-patch-proxmox-and-generic1 stars
Public PoCNeoArtemis37/PHP2shell
Public PoCQuaerendir/cve-2026-109518-audit

Signals come from Exploit-DB, Metasploit, Nuclei and published proof-of-concept repositories. Their absence means nothing was found, not that nothing exists.

Assessment

CVSS: 7.7 (v4.0)
Severity: High
Known exploited: Not listed in CISA KEV
Exploit availability: Public PoC
Published: 4 November 2026
Last updated: 5 November 2026
Affected: Debian · Ubuntu · apt
Assigner: canonical

CVSS vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

At the source

EUVD (ENISA)

References

Community proofs of concept

No community proof of concept yet. If you have one for a published vulnerability and the right to share it, add it below — it will appear here once reviewed.

Submit a proof of concept

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Before you submit * This vulnerability is already publicly disclosed (it has a published CVE). This material comes only from testing I was authorised to perform. I have the legal right to publish this content and am not breaching any agreement by doing so. It contains no live credentials, personal data, or anything targeting systems I am not authorised to test. I understand it will be reviewed before it appears publicly and may be rejected. I agree to the submission terms.

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