High severity · published Aug 27, 2026
CVE-2026-81522
Cross-tenant database retargeting via dot/NUL injection in namespace strings in the C++ Driver
8.1
CVSS
0.5%
EPSS
No
On KEV
Description
A weakness in the MongoDB C++ Driver's handling of caller-supplied namespace identifiers allows special characters embedded in those identifiers. An application that builds a namespace identifier from untrusted input without validating it may therefore have its operation directed at a different target than intended. This can result in limited unauthorized read and write access to data belonging to another logical tenant of the affected application.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 40% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MO
MongoDB · MongoDB
3.0.0 before 4.5.1 · source: vendor
CD
C++ Driver · Mongodb
3.0.0 before 4.5.2 · source: NVD
Affected product
MO
MongoDB
MongoDB
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