---
title: "CVE-2019-19956\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-2019-19956?format=md
keywords: index, follow
---

# CVE-2019-19956

Publication date 24 December 2019

Last updated 25 August 2025

---

Ubuntu priority

**Low**

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

## Cvss 3 Severity Score

**7.5 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2019-19956?format=md#impact-score)

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## Description

xmlParseBalancedChunkMemoryRecover in parser.c in libxml2 before 2.9.10 has
a memory leak related to newDoc->oldNs.

[Read the notes from the security team](https://ubuntu.com/security/CVE-2019-19956?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| libxml2 | 20.04 LTS focal | Fixed 2.9.10+dfsg-1ubuntu2 |
| 19.10 eoan | Fixed 2.9.4+dfsg1-7ubuntu3.1 |
| 19.04 disco | Ignored end of life |
| 18.04 LTS bionic | Fixed 2.9.4+dfsg1-6.1ubuntu1.3 |
| 16.04 LTS xenial | Fixed 2.9.3+dfsg1-1ubuntu0.7 |
| 14.04 LTS trusty | Fixed 2.9.1+dfsg1-3ubuntu4.13+esm1  Ubuntu Pro |

---

* [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-2019-19956?format=md#patch-details)

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## Notes

---

### [ccdm94](https://launchpad.net/~ccdm94)

the fix for this issue, made available with commit 5a02583c,
was reverted in version 2.9.11 with commit a0a8059b, since
it seems like the fix introduced various memory issues in
libxml2. More information regarding this choice made by
upstream can be seen at:
https://gitlab.gnome.org/GNOME/libxml2/-/issues/161

### 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 |
| --- | --- |
| libxml2 | * Upstream:   [5a02583](https://gitlab.gnome.org/GNOME/libxml2/commit/5a02583c7e683896d84878bd90641d8d9b0d0549) |

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

7.5 · High

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 7.5 · High |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-19956)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2019-19956)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2019-19956)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2019-19956)

### Related Ubuntu Security Notices (USN)

+ [USN-4274-1](https://usn.ubuntu.com/USN-4274-1)
+ libxml2 vulnerabilities
+ 10 February 2020

### Other references

* <https://lists.debian.org/debian-lts-announce/2019/12/msg00032.html>
* <https://www.cve.org/CVERecord?id=CVE-2019-19956>