CVE-2026-9750 — mongo
CVE-2026-9750 is a Reachable Assertion vulnerability. A fix is available — see the affected versions and patch details below.
Metadata name collision on $-prefixed fields causes post-auth server crash
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-9750.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Description
An authenticated user can cause a MongoDB server to crash or return incorrect results by creating documents that interfere with internal metadata processing during query execution. This stems from insufficient separation between user-controlled document fields and internal metadata in certain execution paths.
Affected Products
mongodbmongodbDetection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Fix
Upgrade the affected component to the fixed release for CVE-2026-9750, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2026-9750 in your dependencies?
Find it across , including transitive dependencies.