CVE-2019-9788

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2019-04-26 · updated 2026-06-17
Weakness: CWE-787

Description

Mozilla developers and community members reported memory safety bugs present in Firefox 65, Firefox ESR 60.5, and Thunderbird 60.5. 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 < 60.6, Firefox ESR < 60.6, and Firefox < 66.

Affected products

Mozilla Firefox: before 60.6.0; before 66.0 — fixed in 60.6.0, 66.0
Mozilla Thunderbird: before 60.6.0 — fixed in 60.6.0
Red Hat Enterprise Linux: 8.0
RedHat Enterprise Linux Eus: 8.1, 8.2, 8.4
RedHat Enterprise Linux Server Aus: 8.2, 8.4
RedHat Enterprise Linux Server Tus: 8.2, 8.4

How to fix

Upgrade to a fixed version: Mozilla Firefox 60.6.0, 66.0; Mozilla Thunderbird 60.6.0. Check the vendor advisory for mitigations.

References

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