High (7.5) in mozilla. EPSS 0.7% chance of exploitation in the next 30 days.
When installing an add-on, Firefox verified the signature before prompting the user; but while the user was confirming the prompt, the underlying add-on file could have been modified and Firefox would not have noticed. This vulnerability affects Firefox < 98, Firefox ESR < 91.7, and Thunderbird < 91.7.
Severity
CVSS 3.1
7.5 high
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
0.7% chance of exploitation in the next 30 days; higher than 51% of CVEs (scores of 2026-10-31)