CVE-2026-4721

Description

Memory safety bugs present in Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148. 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 was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

References

https://www.mozilla.org/security/advisories/mfsa2026-24/

https://www.mozilla.org/security/advisories/mfsa2026-23/

https://www.mozilla.org/security/advisories/mfsa2026-22/

https://www.mozilla.org/security/advisories/mfsa2026-21/

https://www.mozilla.org/security/advisories/mfsa2026-20/

https://bugzilla.mozilla.org/buglist.cgi?bug_id=2013762%2C2015291%2C2016591%2C2016661%2C2016664%2C2017303%2C2017894%2C2018090%2C2018196%2C2018379%2C2019112%2C2022090%2C2022243%2C2022351%2C2022478%2C2022676

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3

EPSS