Medium severity · published Oct 13, 2026
CVE-2026-103965
Fixed values in MongoDB Server $bucket stage may be misread as field references
5.4
CVSS
0.2%
EPSS
No
On KEV
Description
An issue in MongoDB Server's aggregation framework can cause certain constant values to be handled incorrectly during internal query rewriting. Under certain conditions, an authenticated user with read access may receive field values in aggregation output that the query did not intend to return.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 4% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MO
MongoDB · MongoDB
8.3.0 before 8.3.13; 8.0 before 8.0.34; 7.0 before 7.0.45; 9.0 before 9.0.4 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-103965
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-103965
jira.mongodb.org
https://jira.mongodb.org/browse/SERVER-134618
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