EncryptingOutputStream was susceptible to exposing uninitialized data. This issue could only be abused in order to write data to a local disk which may have implications for private browsing mode. This vulnerability affects Firefox ESR < 115.6 and Firefox < 121.
121121115.6115.6Exploitability
AV:NAC:LPR:NUI:RScope
S:UImpact
C:HI:NA:N6.5/CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N