Missing Authorization in MongoDB Server - CVE-2026-18709
Published: August 18, 2026
Vulnerability identifier: #VU144147
CSH Severity: Low
CVSS v4: 5.9 [CVSS:4.0/AV:A/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-18709
CWE-ID: CWE-862
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause cross-shard data inconsistency, corrupt the cluster clock, and violate transaction atomicity guarantees.
The vulnerability exists due to missing authorization in sharded transaction commit/abort handling when handling commit or abort operations for an in-progress prepared transaction on a shard. A remote user can send commit or abort operations directly to a shard to cause cross-shard data inconsistency, corrupt the cluster clock, and violate transaction atomicity guarantees.
Exploitation requires direct network access to a shard.
Affected software
MongoDB Server
How to mitigate CVE-2026-18709
Install security update from vendor's website.
MongoDB Server - addressed in versions 7.0.40, 8.0.29, 8.3.8