MongoDB 3.4.x before 3.4.10, and 3.5.x-development, has a disabled-by-default configuration setting, networkMessageCompressors (aka wire protocol compression), which exposes a vulnerability when enabled that could be exploited by a malicious attacker to deny service or modify memory.
Severity
CVSS 3.0
9.1 critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
EPSS
1.6% chance of exploitation in the next 30 days; higher than 75% of CVEs (scores of 2026-10-31)