CVE-2026-74989

CRITICAL 9.8CVE-2026-74989 · Published 18/08/2026 · updated 28/10/2026

Package	Affected versions	Patched versions
firefox mozilla	`< 154.0.0`	`154.0.0`
thunderbird mozilla	`< 154.0`	`154.0`

Description

Internally found bugs present in Firefox 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154 and Thunderbird 154.

References

bugzilla.mozilla.org/buglist.cgi · Not Applicable
bugzilla.mozilla.org/buglist.cgi · Not Applicable
mozilla.org/security/advisories/mfsa2026-74 · Vendor Advisory
mozilla.org/security/advisories/mfsa2026-78 · Vendor Advisory

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