High severity · published Aug 27, 2026
CVE-2026-81525
Cross-tenant database retargeting via dot/NUL injection in namespace strings in the PHP Driver
8.1
CVSS
0.5%
EPSS
No
On KEV
Description
The MongoDB client library for PHP does not sufficiently sanitize special elements in application-supplied namespace identifiers before using them to construct the target namespace for database operations. An application that incorporates untrusted text into these identifiers may have operations silently directed at a different storage location than the one the application intended.
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 42% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MO
MongoDB · MongoDB
before 1.21.6; 2.0.0 before 2.4.1 · source: vendor
PD
Php Driver · Mongodb
before 1.21.6; 2.0.0 before 2.4.1 · source: NVD
PL
Php Library · Mongodb
before 1.21.4; 2.0.0 before 2.4.1 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-81525
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-81525
Product
https://github.com/mongodb/mongo-php-driver/releases/tag/1.21.6
Product
https://github.com/mongodb/mongo-php-driver/releases/tag/2.4.1
Product
https://github.com/mongodb/mongo-php-library/releases/tag/1.21.4
Product
https://github.com/mongodb/mongo-php-library/releases/tag/2.4.1
Vendor Advisory
https://jira.mongodb.org/browse/PHPLIB-1927
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