Cross-tenant database retargeting via dot/NUL injection in namespace strings in libmongocrypt
Summary
| CVE | CVE-2026-81523 |
|---|---|
| State | PUBLISHED |
| Assigner | mongodb |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-27 20:18:50 UTC |
| Updated | 2026-08-28 21:16:15 UTC |
| Description | A missing input-validation issue in MongoDB libmongocrypt's automatic-encryption context setup allows a caller-supplied database identifier to be accepted without sanitization. The resulting impact is limited to incorrect schema selection, which may lead to limited disclosure or modification of information handled by the application. |
Risk And Classification
Primary CVSS: v4.0 2 LOW from [email protected]
CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS: 0.000740000 probability, percentile 0.000760000 (date 2026-08-31)
Problem Types: CWE-74 | CWE-74 CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 2 | LOW | CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 2 | LOW | CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N |
| 3.1 | [email protected] | Secondary | 4.4 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
| 3.1 | CNA | CVSS | 4.4 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
CVSS v4.0 Breakdown
Attack Vector
LocalAttack Complexity
LowAttack Requirements
PresentPrivileges Required
LowUser Interaction
NoneConfidentiality
LowIntegrity
LowAvailability
NoneSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
LowIntegrity
LowAvailability
NoneCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | MongoDB | Libmongocrypt | affected 1.0.0 1.20.3 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| jira.mongodb.org/browse/MONGOCRYPT-977 | [email protected] | jira.mongodb.org | |
| github.com/mongodb/libmongocrypt/releases/tag/1.20.3 | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.