CVE-2024-6615: Memory safety bugs fixed in Firefox 128 and Thunderbird 128

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-07-09 · updated 2026-06-17
Weakness: CWE-787

Description

Memory safety bugs present in Firefox 127 and Thunderbird 127. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 128 and Thunderbird < 128.

Affected products

Mozilla Firefox: before 128.0 — fixed in 128.0
Mozilla Thunderbird: before 128.0 — fixed in 128.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 128.0; Mozilla Thunderbird 128.0. Check the vendor advisory for mitigations.

References

https://bugzilla.mozilla.org/buglist.cgi?bug_id=1892875%2C1894428%2C1898364
https://www.mozilla.org/security/advisories/mfsa2024-29/
https://www.mozilla.org/security/advisories/mfsa2024-32/
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1892875%2C1894428%2C1898364
https://www.mozilla.org/security/advisories/mfsa2024-29/
https://www.mozilla.org/security/advisories/mfsa2024-32/

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