---
title: "CVE-2015-8540\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-2015-8540?format=md
keywords: index, follow
---

# CVE-2015-8540

Publication date 11 December 2015

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**8.8 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2015-8540?format=md#impact-score)

Toggle side navigation

## Description

Integer underflow in the png\_check\_keyword function in pngwutil.c in libpng
0.90 through 0.99, 1.0.x before 1.0.66, 1.1.x and 1.2.x before 1.2.56,
1.3.x and 1.4.x before 1.4.19, and 1.5.x before 1.5.26 allows remote
attackers to have unspecified impact via a space character as a keyword in
a PNG image, which triggers an out-of-bounds read.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| chromium-browser | 15.10 wily | Not affected |
| 15.04 vivid | Not affected |
| 14.04 LTS trusty | Not in release |
| 12.04 LTS precise | Not affected |
| firefox | 15.10 wily | Not affected |
| 15.04 vivid | Not affected |
| 14.04 LTS trusty | Not in release |
| 12.04 LTS precise | Not affected |
| libpng | 15.10 wily | Fixed 1.2.51-0ubuntu3.15.10.2 |
| 15.04 vivid | Fixed 1.2.51-0ubuntu3.15.04.2 |
| 14.04 LTS trusty | Fixed 1.2.50-1ubuntu2.14.04.2 |
| 12.04 LTS precise | Fixed 1.2.46-3ubuntu4.2 |
| thunderbird | 15.10 wily | Not affected |
| 15.04 vivid | Not affected |
| 14.04 LTS trusty | Not in release |
| 12.04 LTS precise | Not affected |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)
* [Patch details](https://ubuntu.com/security/CVE-2015-8540?format=md#patch-details)

### Patch details

For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)

| Package | Patch details |
| --- | --- |
| libpng | * Upstream:   <http://sourceforge.net/p/libpng/code/ci/d9006f683c641793252d92254a75ae9b815b42ed/> * Upstream:   [520b373](https://github.com/glennrp/libpng/commit/520b373ee53e92dce93917fea5a609b2a0291472) |

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

8.8 · High

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 8.8 · High |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-8540)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2015-8540)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2015-8540)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2015-8540)

### Related Ubuntu Security Notices (USN)

+ [USN-2861-1](https://usn.ubuntu.com/USN-2861-1)
+ libpng vulnerabilities
+ 6 January 2016

### Other references

* <http://www.openwall.com/lists/oss-security/2015/12/10/6>
* <https://www.cve.org/CVERecord?id=CVE-2015-8540>