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CVE.org (no NVD analysis yet)· CNA canonical

CVE-2026-109518: APT RCE via hard link reuse

HighCVSS 7.7 · v4.0—Proof of concept Fix available

Noroxi assessment

Priority: Monitor (action score 30/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.92% (FIRST EPSS); higher than 61% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No special conditions are required; it is repeatable.
  • Fixed version: Debian APT 1.2.36, 1.4.12, 1.6.19; Ubuntu APT 1.0.1ubuntu2.24+esm4, 1.2.36+esm1, 1.6.19+esm1.

Low priority for now. Upgrade to Debian APT 1.2.36, 1.4.12, 1.6.19; Ubuntu APT 1.0.1ubuntu2.24+esm4, 1.2.36+esm1, 1.6.19+esm1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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

Published
Nov 4, 2026
Updated
Nov 12, 2026
EPSS
0.9% · 61th percentile

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.9%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · canonical
7.7
NVD has not scored this yet; the score shown is the CNA’s.

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-109518

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (canonical). Independent of NVD's CPE analysis and usually ahead of it.

  • Debian APT

    • before 1.2.36affected · dpkg
    • 1.4.0 and later · before 1.4.12affected · dpkg
    • 1.6.0 and later · before 1.6.19affected · dpkg
    • 1.8.0 and later · before 1.8.2.4affected · dpkg
    • 1.8.3 and later · up to and including 1.8.5affected · dpkg
    • 2.0.0 and later · before 2.0.12affected · dpkg
    • 2.2.0 and later · before 2.2.5affected · dpkg
    • 2.4.0 and later · before 2.4.15affected · dpkg
    • 2.6.0 and later · before 2.6.2affected · dpkg
    • 2.8.0 and later · before 2.8.4affected · dpkg

  • Ubuntu APT

    • before 1.0.1ubuntu2.24+esm4affected · dpkg
    • 1.2.0 and later · before 1.2.36+esm1affected · dpkg
    • 1.6.0 and later · before 1.6.19+esm1affected · dpkg
    • 2.0.0 and later · before 2.0.12+esm1affected · dpkg
    • 2.4.0 and later · before 2.4.15ubuntu0.1affected · dpkg
    • 2.8.0 and later · before 2.8.4ubuntu0.1affected · dpkg
    • 3.2.0 and later · before 3.2.1ubuntu0.1affected · dpkg
    • 3.3.0 and later · before 3.3.3ubuntu0.1affected · dpkg

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Alpine:v3.24aptbefore 3.2.1-r03.2.1-r0
Debian:12aptbefore 2.6.22.6.2
Debian:13aptbefore 3.0.43.0.4
Debian:14aptbefore 3.3.63.3.6

Same product

debian: all records

Other highest-scoring records for the same primary product.

  • CVE-2020-3810Missing input validation in the ar/tar implementations of APT before version 2.1.2 could result in denial of service when processing…
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Debian APT1.2.36Vendor (CNA)
Debian APT1.4.12Vendor (CNA)
Debian APT1.6.19Vendor (CNA)
Debian APT1.8.2.4Vendor (CNA)
Debian APT2.0.12Vendor (CNA)
Debian APT2.2.5Vendor (CNA)
Debian APT2.4.15Vendor (CNA)
Debian APT2.6.2Vendor (CNA)
Debian APT2.8.4Vendor (CNA)
Debian APT3.0.4Vendor (CNA)
Debian APT3.2.1Vendor (CNA)
Debian APT3.3.6Vendor (CNA)
Ubuntu APT1.0.1ubuntu2.24+esm4Vendor (CNA)
Ubuntu APT1.2.36+esm1Vendor (CNA)
Ubuntu APT1.6.19+esm1Vendor (CNA)
Ubuntu APT2.0.12+esm1Vendor (CNA)
Ubuntu APT2.4.15ubuntu0.1Vendor (CNA)
Ubuntu APT2.8.4ubuntu0.1Vendor (CNA)
Ubuntu APT3.2.1ubuntu0.1Vendor (CNA)
Ubuntu APT3.3.3ubuntu0.1Vendor (CNA)
alpine:apt3.2.1-r0 · Alpine:v3.24Package registry (OSV)
debian:apt2.6.2 · Debian:12Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×2

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:02026-11-04
Proof-of-concept repository on GitHubstars:22026-11-05

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. First PoC-1 d
  2. Published
  3. Fix recordedsame day
  4. TodayNov 13, 2026+9 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Not on record for this CVE: patch commit or PR link · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
P
Scope
X

Weakness class (CWE)

CWE-62 · UNIX Hard Link

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. SSVC exploitation— → none
  2. Exploit maturity— → poc
  3. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records