VULNERABILITY INTELLIGENCE
CVE-2026-9749
CVSS score6.5 MEDIUM
EPSS probability0.27%
CISA KEVNot currently listed
Published2026-06-09
Last modified2026-07-23
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Description
This issue can occur when running an aggregation pipeline that uses the internal $exchange stage configured with key-range partitioning and order-preserving delivery. If a single key range produces enough documents to fill its exchange buffer (that is, many results are routed to the same consumer), the server reaches the code path where a full per-consumer buffer is detected but the internal "high watermark" for that key range is not updated as intended.
Weakness classification
- cna@mongodb.com: CWE-617
Primary references
- cna@mongodb.com — Patch, Vendor Advisory