CVE-2019-11759

Name: CVE-2019-11759
Creator: NVD / NIST
Published: 2020-01-08T20:15:12.623+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 1.80%

Last modified Jun 17, 2026

CVE-2019-11759 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. An attacker could have caused 4 bytes of HMAC output to be written past the end of a buffer stored on the stack. This could be used by an attacker to execute arbitrary code or more likely lead to a crash. EPSS estimates a 1.80% chance of exploitation in the next 30 days.

Description

An attacker could have caused 4 bytes of HMAC output to be written past the end of a buffer stored on the stack. This could be used by an attacker to execute arbitrary code or more likely lead to a crash. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.

Metrics

CVSS 3.1

8.8/10

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

EPSS Probability

1.80%

75.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-120

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 70.0
Mozilla	Firefox Esr	< 68.2
Mozilla	Thunderbird	< 68.2
Canonical	Ubuntu Linux	16.04

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1577953Issue Tracking, Permissions Required
https://security.gentoo.org/glsa/202003-10Third Party Advisory
https://usn.ubuntu.com/4335-1/Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2019-33/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2019-34/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2019-35/Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1577953Issue Tracking, Permissions Required
https://security.gentoo.org/glsa/202003-10Third Party Advisory
https://usn.ubuntu.com/4335-1/Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2019-33/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2019-34/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2019-35/Vendor Advisory

Timeline

Published: Jan 8, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-11759?

How severe is CVE-2019-11759?

CVE-2019-11759 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 1.80% probability of exploitation in the next 30 days.

How do I fix CVE-2019-11759?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-11759?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST