If websocket data is sent with mixed text and binary in a single message, the binary data can be corrupted. This can result in an out-of-bounds read with the read memory sent to the originating server in response. This vulnerability affects Firefox < 60.
Severity
CVSS 3.0
7.5 high
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
1.6% chance of exploitation in the next 30 days; higher than 76% of CVEs (scores of 2026-10-31)