CVE-2026-9749: This issue can occur when running an aggregation pipeline that uses the internal $exchange stage configured with key-range partitioning and order-preserving…

PriorityP336medium6.5CVSS 3.1

AVNACLPRLUINSUCNINAH

EPSS

0.27%

18.5th percentile

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.

Affected

4 ranges

Vendor	Product	Version range	Fixed in
mongodb	mongodb_server	>= 7.0.0 < 7.0.35	7.0.35
mongodb	mongodb_server	>= 8.0.0 < 8.0.24	8.0.24
mongodb	mongodb_server	>= 8.2.0 < 8.2.10	8.2.10
mongodb	mongodb_server	>= 8.3.0 < 8.3.3	8.3.3

CVSS provenance

nvdv3.16.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvdv4.07.1HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.