Medium severity · published Aug 11, 2026
CVE-2026-18704
Improper Authorization in MongoDB Aggregation Framework Allows Read-Only User to Perform Unauthorized Write Operations
6.5
CVSS
0.3%
EPSS
No
On KEV
Description
An issue in MongoDB Server's aggregation framework could allow an authenticated user with only read privileges to perform write operations against collections they should not be able to modify. This is due to an internal-use aggregation stage being reachable by external clients without an appropriate authorization check on its embedded operations.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 21% 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 8.3.8 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-18704
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-18704
Vendor Advisory
https://jira.mongodb.org/browse/SERVER-129936
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