Cross-schema data access via unsanitized database identifiers
Published Aug 27, 2026 · Updated Aug 27, 2026
Improper input validation in MongoDB libmongocrypt before 1.20.3 allows attackers to access unintended schema data via a database identifier. During automatic-encryption context setup, the library accepts a caller-supplied database identifier without sanitization and uses it to select a schema. Exploitation requires control of the identifier passed by a consuming driver or application, and the resulting impact is limited to disclosure or modification of application-handled information.
Summary
What happened
Improper input validation in MongoDB libmongocrypt before 1.20.3 allows attackers to access unintended schema data via a database identifier. During automatic-encryption context setup, the library accepts a caller-supplied database identifier without sanitization and uses it to select a schema. Exploitation requires control of the identifier passed by a consuming driver or application, and the resulting impact is limited to disclosure or modification of application-handled information.
The record
- CVE
- CVE-2026-81523
- Published
- Aug 27, 2026
- Updated
- Aug 27, 2026
- Vendor
- MongoDB
- Product
- libmongocrypt
- Classifications
- T1213
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Aug 27, 2026CVE publishedPublication date reported by the CVE source.
- Aug 27, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.0.0 <1.20.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo