Pre-authentication use-after-free in MongoDB Server replica set primary catch-up
Not on CISA's list of exploited flaws, and not in the news we track.
9.5of 10, critical
Reading the vendor advisory
Fix it in your code
Each opens with a short prompt that points at Global Hack Map's public runbook for CVE-2026-118383. Nothing runs until you send it.
A use-after-free in the replication component of MongoDB Server can occur when a newly elected replica set primary completes catch-up. The condition can be caused by requests that do not require authentication, and may result in the server terminating unexpectedly or, under certain conditions, arbitrary code execution in the context of the server process. Replica set members are affected, including the shard and config server replica set members of sharded clusters; standalone mongod instances are not.
You are affected if
The fix