CVE-2026-9749
Using MaxKey() may crash the server
EPSS 0.27%
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.
How to fix CVE-2026-9749
To remediate CVE-2026-9749, upgrade the affected package to a fixed version below.
- —upgrade to 7.0.35 or later
Is CVE-2026-9749 being exploited?
Low — EPSS is 0.3%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- >= 7.0.0, < 7.0.35, >= 8.0.0, < 8.0.24, >= 8.2.0, < 8.2.10, >= 8.3.0, < 8.3.3
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS: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 |