Vulnerability in MongoDB Bi Connector
CVE-2026-81520
A network-reachable client that has not yet authenticated can hold a MongoDB Connector for BI authentication session open indefinitely by beginning a SASL-based login exchange and then declining to complete it. Because the negotiation loop had no overall time bound and the read from the client had no deadline, each such session retains a worker, a client connection slot, and its associated backend database connections until the process is restarted. Repeated use of this behavior can consume the configured connection capacity and prevent legitimate users from establishing new sessions.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-81520?
- CVE-2026-81520 is a high-severity vulnerability in MongoDB Bi Connector, classified under CWE-1088. CVSS score: 7.5/10. Published 2026-08-28.
- How severe is CVE-2026-81520?
- High severity. CVSS v3 base score is 7.5 out of 10.