---
title: "CVE-2018-12026\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2018-12026?format=md
keywords: index, follow
---

# CVE-2018-12026

Publication date 17 June 2018

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**9.8 · Critical**

[Score breakdown](https://ubuntu.com/security/CVE-2018-12026?format=md#impact-score)

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## Description

During the spawning of a malicious Passenger-managed application,
SpawningKit in Phusion Passenger 5.3.x before 5.3.2 allows such
applications to replace key files or directories in the spawning
communication directory with symlinks. This then could result in arbitrary
reads and writes, which in turn can result in information disclosure and
privilege escalation.

[Read the notes from the security team](https://ubuntu.com/security/CVE-2018-12026?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| passenger | 22.04 LTS jammy | Not affected |
| 21.10 impish | Not affected |
| 21.04 hirsute | Ignored end of life |
| 20.10 groovy | Ignored end of life |
| 20.04 LTS focal | Not affected |
| 19.10 eoan | Ignored end of life |
| 19.04 disco | Ignored end of life |
| 18.10 cosmic | Ignored end of life |
| 18.04 LTS bionic | Not affected |
| 17.10 artful | Ignored end of life |
| 16.04 LTS xenial | Not affected |
| 14.04 LTS trusty | Not in release |
| ruby-passenger | 22.04 LTS jammy | Not in release |
| 21.10 impish | Not in release |
| 21.04 hirsute | Not in release |
| 20.10 groovy | Not in release |
| 20.04 LTS focal | Not in release |
| 19.10 eoan | Not in release |
| 19.04 disco | Not in release |
| 18.10 cosmic | Not in release |
| 18.04 LTS bionic | Not in release |
| 17.10 artful | Not in release |
| 16.04 LTS xenial | Not in release |
| 14.04 LTS trusty | Not in release |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)

## Notes

---

### [rodrigo-zaiden](https://launchpad.net/~rodrigo-zaiden)

xenial, bionic, focal and impish have version 5.0.x and are
not affected because the issue was introduced in 5.3.0, with a major
overhaul in SpawningKit.

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

9.8 · Critical

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Privileges required | None |
  | User interaction | None |
  | Scope | Unchanged |
  | Confidentiality impact | High |
  | Integrity impact | High |
  | Availability impact | High |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 9.8 · Critical |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-12026)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2018-12026)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2018-12026)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2018-12026)

### Other references

* <https://blog.phusion.nl/2018/06/12/passenger-5-3-2-various-security-fixes/>
* <https://blog.phusion.nl/passenger-5-3-2>
* <https://www.cve.org/CVERecord?id=CVE-2018-12026>