---
title: "CVE-2018-5131\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-2018-5131?format=md
keywords: index, follow
---

# CVE-2018-5131

Publication date 14 March 2018

Last updated 25 August 2025

---

Ubuntu priority

**Low**

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

## Cvss 3 Severity Score

**5.9 · Medium**

[Score breakdown](https://ubuntu.com/security/CVE-2018-5131?format=md#impact-score)

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## Description

Under certain circumstances the "fetch()" API can return transient local
copies of resources that were sent with a "no-store" or "no-cache" cache
header instead of downloading a copy from the network as it should. This
can result in previously stored, locally cached data of a website being
accessible to users if they share a common profile while browsing. This
vulnerability affects Firefox ESR < 52.7 and Firefox < 59.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| firefox | 18.04 LTS bionic | Fixed 59.0.1+build1-0ubuntu1 |
| 17.10 artful | Fixed 59.0+build5-0ubuntu0.17.10.1 |
| 16.04 LTS xenial | Fixed 59.0+build5-0ubuntu0.16.04.1 |
| 14.04 LTS trusty | Fixed 59.0+build5-0ubuntu0.14.04.1 |

---

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

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

5.9 · Medium

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 5.9 · Medium |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-5131)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2018-5131)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2018-5131)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2018-5131)

### Related Ubuntu Security Notices (USN)

+ [USN-3596-1](https://usn.ubuntu.com/USN-3596-1)
+ Firefox vulnerabilities
+ 14 March 2018

### Other references

* <https://www.mozilla.org/en-US/security/advisories/mfsa2018-06/>
* <https://www.cve.org/CVERecord?id=CVE-2018-5131>