MongoDB libmongocrypt up to 1.20.2 input validation

CVSS Meta Temp Score
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CTI Interest Score
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5.2$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in MongoDB libmongocrypt up to 1.20.2. This affects an unknown function. Performing a manipulation results in input validation. This vulnerability is reported as CVE-2026-81523. The attack is possible to be carried out remotely. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in MongoDB libmongocrypt up to 1.20.2. This affects an unknown functionality. The manipulation with an unknown input leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-81523 since 08/27/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 341354 (Linux Distros Unpatched Vulnerability : CVE-2026-81523), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.20.3 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (341354) and CERT Bund (WID-SEC-2026-3066). Be aware that VulDB is the high quality source for vulnerability data.

Affected

  • Open Source MongoDB

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.2

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 4.4
CNA Vector (mongodb): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 341354
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-81523

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: libmongocrypt 1.20.3

Timelineinfo

08/27/2026 Advisory disclosed
08/27/2026 +0 days CVE reserved
08/27/2026 +0 days VulDB entry created
08/31/2026 +4 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-81523 (🔒)
GCVE (CVE): GCVE-0-2026-81523
GCVE (VulDB): GCVE-100-396327
CERT Bund: WID-SEC-2026-3066 - MongoDB Clients: Mehrere Schwachstellen

Entryinfo

Created: 08/27/2026 22:32
Updated: 08/31/2026 16:45
Changes: 08/27/2026 22:32 (76), 08/30/2026 10:34 (7), 08/31/2026 16:45 (2)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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