CVE-2019-9800: Critical severity Mozilla Thunderbird vulnerability

Published May 21, 2019
·
Updated

Last updated 25 August 2025

Other sources

Mozilla developers and community members Olli Pettay, Bogdan Tara, Jan de Mooij, Jason Kratzer, Jan Varga, Gary Kwong, Tim Guan-tin Chien, Tyson Smith, Ronald Crane, and Ted Campbell reported memory safety bugs present in Firefox 66 and Firefox ESR 60.6. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code.

Mozilla developers and community members Olli Pettay, Bogdan Tara, Jan de Mooij, Jason Kratzer, Jan Varga, Gary Kwong, Tim Guan-tin Chien, Tyson Smith, Ronald Crane, and Ted Campbell reported memory safety bugs present in Firefox 66, Firefox ESR 60.6, and Thunderbird 60.6. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code.

— Mozilla

Mozilla developers and community members reported memory safety bugs present in Firefox 66 and Firefox ESR 60.6. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code.

External Reference:

https://www.mozilla.org/en-US/security/advisories/mfsa2019-14/#CVE-2019-9800

— Red Hat

Mozilla developers and community members reported memory safety bugs present in Firefox 66, Firefox ESR 60.6, and Thunderbird 60.6. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Thunderbird < 60.7, Firefox < 67, and Firefox ESR < 60.7.

— Launchpad

Affected Software

9 affected componentsFixes available
Mozilla Thunderbird<60.7
60.7
Mozilla Firefox<67.0
Mozilla Firefox ESR<60.7
Mozilla Thunderbird<60.7
Mozilla Firefox<67
67
Mozilla Firefox ESR<60.7
60.7
debian/firefox
152.0-1
debian/firefox-esr
115.14.0esr-1~deb11u1140.11.0esr-1~deb11u1140.10.2esr-1~deb12u1140.12.0esr-1~deb12u1140.10.2esr-1~deb13u1140.12.0esr-1~deb13u1140.11.0esr-1140.12.0esr-1
debian/thunderbird
1:115.12.0-1~deb11u11:140.12.0esr-1~deb11u11:140.10.1esr-1~deb12u11:140.11.0esr-1~deb12u11:140.10.1esr-1~deb13u11:140.11.0esr-1~deb13u11:140.11.0esr-11:140.12.0esr-1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade Thunderbird to a version that resolves this vulnerability.

    Fixed in 60.7
  2. Upgrade

    Upgrade Firefox to a version that resolves this vulnerability.

    Fixed in 67
  3. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 60.7
  4. Upgrade

    Upgrade debian/firefox to a version that resolves this vulnerability.

    Fixed in 152.0-1
  5. Upgrade

    Upgrade debian/firefox-esr to a version that resolves this vulnerability.

    Fixed in 115.14.0esr-1~deb11u1Fixed in 140.11.0esr-1~deb11u1Fixed in 140.10.2esr-1~deb12u1Fixed in 140.12.0esr-1~deb12u1Fixed in 140.10.2esr-1~deb13u1Fixed in 140.12.0esr-1~deb13u1Fixed in 140.11.0esr-1Fixed in 140.12.0esr-1
  6. Upgrade

    Upgrade debian/thunderbird to a version that resolves this vulnerability.

    Fixed in 1:115.12.0-1~deb11u1Fixed in 1:140.12.0esr-1~deb11u1Fixed in 1:140.10.1esr-1~deb12u1Fixed in 1:140.11.0esr-1~deb12u1Fixed in 1:140.10.1esr-1~deb13u1Fixed in 1:140.11.0esr-1~deb13u1Fixed in 1:140.11.0esr-1Fixed in 1:140.12.0esr-1
  7. Upgrade

    Upgrade debian/firefox-esr to a version that resolves this vulnerability.

    Fixed in 115.14.0esr-1~deb11u1
  8. Upgrade

    Upgrade debian/firefox-esr to a version that resolves this vulnerability.

    Fixed in 140.11.0esr-1~deb11u1
  9. Upgrade

    Upgrade debian/firefox-esr to a version that resolves this vulnerability.

    Fixed in 140.10.2esr-1~deb12u1
  10. Upgrade

    Upgrade debian/firefox-esr to a version that resolves this vulnerability.

    Fixed in 140.12.0esr-1~deb12u1
  11. Upgrade

    Upgrade debian/firefox-esr to a version that resolves this vulnerability.

    Fixed in 140.10.2esr-1~deb13u1
  12. Upgrade

    Upgrade debian/firefox-esr to a version that resolves this vulnerability.

    Fixed in 140.12.0esr-1~deb13u1
  13. Upgrade

    Upgrade debian/firefox-esr to a version that resolves this vulnerability.

    Fixed in 140.11.0esr-1
  14. Upgrade

    Upgrade debian/firefox-esr to a version that resolves this vulnerability.

    Fixed in 140.12.0esr-1
  15. Upgrade

    Upgrade debian/thunderbird to a version that resolves this vulnerability.

    Fixed in 1:115.12.0-1~deb11u1
  16. Upgrade

    Upgrade debian/thunderbird to a version that resolves this vulnerability.

    Fixed in 1:140.12.0esr-1~deb11u1
  17. Upgrade

    Upgrade debian/thunderbird to a version that resolves this vulnerability.

    Fixed in 1:140.10.1esr-1~deb12u1
  18. Upgrade

    Upgrade debian/thunderbird to a version that resolves this vulnerability.

    Fixed in 1:140.11.0esr-1~deb12u1
  19. Upgrade

    Upgrade debian/thunderbird to a version that resolves this vulnerability.

    Fixed in 1:140.10.1esr-1~deb13u1
  20. Upgrade

    Upgrade debian/thunderbird to a version that resolves this vulnerability.

    Fixed in 1:140.11.0esr-1~deb13u1
  21. Upgrade

    Upgrade debian/thunderbird to a version that resolves this vulnerability.

    Fixed in 1:140.11.0esr-1
  22. Upgrade

    Upgrade debian/thunderbird to a version that resolves this vulnerability.

    Fixed in 1:140.12.0esr-1

Event History

May 21, 2019
CVE Published
via Mozilla·12:00 AM
May 22, 2019
Data Sourced
via Red Hat·01:46 AM
DescriptionSeverityAffected Software
Jul 23, 2019
CVE Published
via MITRE·01:26 PM
Data Sourced
via MITRE·01:26 PM
DescriptionWeakness
Jan 11, 2024
Data Sourced
via Launchpad·11:33 PM
Description
Feb 19, 2026
Data Sourced
via Ubuntu·05:59 PM
RemedyDescriptionSeverityAffected Software
Jun 18, 2026
Data Sourced
via Debian·04:01 AM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

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Frequently Asked Questions

1

What is the severity of CVE-2019-9800?

The severity of CVE-2019-9800 is critical, with a severity value of 9.

2

Which versions of Firefox are affected by CVE-2019-9800?

Firefox versions up to 67.0 are affected by CVE-2019-9800.

3

Which versions of Firefox ESR are affected by CVE-2019-9800?

Firefox ESR versions up to 60.7 are affected by CVE-2019-9800.

4

Which versions of Thunderbird are affected by CVE-2019-9800?

Thunderbird versions up to 60.7 are affected by CVE-2019-9800.

5

Where can I find more information about CVE-2019-9800?

More information about CVE-2019-9800 can be found at the following references: [Reference 1](https://bugzilla.mozilla.org/buglist.cgi?bug_id=1540166%2C1534593%2C1546327%2C1540136%2C1538736%2C1538042%2C1535612%2C1499719%2C1499108%2C1538619%2C1535194%2C1516325%2C1542324%2C1542097%2C1532465%2C1533554%2C1541580), [Reference 2](https://www.mozilla.org/en-US/security/advisories/mfsa2019-13/), [Reference 3](https://www.mozilla.org/security/advisories/mfsa2019-13/).

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