CVE-2026-18710: MongoDB Driver Info Disclosure Flaw

CVE-2026-18710 Overview

CVE-2026-18710 is an information disclosure vulnerability in a MongoDB driver component. The driver writes sensitive configuration information to application log output in cleartext during routine client initialization. The exposed data includes a credential used for outbound network connectivity. Logging occurs automatically as part of normal operation and requires no special privileges to trigger. Any party able to read the application's logs or downstream log-aggregation storage can recover the credential. The recovered credential can then be reused to authenticate to the associated network infrastructure. This weakness is classified as insertion of sensitive information into log files [CWE-532] and affects confidentiality only.

Critical Impact
A local actor with log-read access can recover cleartext credentials from application logs and reuse them against upstream network infrastructure.

Affected Products

MongoDB Java Driver (see MongoDB Jira Issue JAVA-6266)
Applications embedding the affected driver component
Downstream log-aggregation systems that ingest driver output

Discovery Timeline

2026-08-11 - CVE-2026-18710 published to NVD
2026-08-12 - Last updated in NVD database

Technical Details for CVE-2026-18710

Vulnerability Analysis

The MongoDB driver emits configuration data to its logging subsystem during client initialization. One of the emitted fields contains a credential the driver uses for outbound network connectivity. The credential is written in cleartext rather than being redacted, masked, or omitted. Because initialization runs on every client instantiation, the credential is disclosed as part of the driver's expected startup behavior. No attacker interaction with the application is required to produce the log entry.

An actor with read access to the application logs, log shipping pipelines, or centralized log storage can extract the credential and authenticate to the associated network infrastructure. The impact is scoped to confidentiality of the disclosed credential and any resources that credential unlocks. The issue does not affect integrity or availability of the driver itself.

Root Cause

The root cause is missing sanitization in the driver's initialization logging path. Sensitive configuration fields are serialized into log records without redaction. This matches the pattern described by CWE-532: Insertion of Sensitive Information into Log File.

Attack Vector

Exploitation is local and passive. An attacker does not send input to the vulnerable component. Instead, the attacker reads logs produced by a benign application run. Access paths include local log files on application hosts, mounted log volumes, SIEM indices, backup archives, and third-party log-forwarding destinations. Any account with read permission on those artifacts can recover the credential. See the MongoDB Jira Issue JAVA-6266 for driver-specific technical details.

Detection Methods for CVE-2026-18710

Indicators of Compromise

Log entries generated during MongoDB driver client initialization that contain connection configuration fields in cleartext.
Access events on log files, log directories, or SIEM indices by accounts that do not routinely require log access.
Authentication events on upstream network infrastructure originating from hosts or identities that should not hold the exposed credential.

Detection Strategies

Grep application logs and log-aggregation stores for known credential patterns emitted by the driver during initialization.
Correlate credential-string matches in log storage with subsequent authentication events using the same credential from unexpected sources.
Baseline read access to log storage and alert on new principals, service accounts, or export operations touching driver logs.

Monitoring Recommendations

Enable audit logging on the network infrastructure the exposed credential can authenticate to, and monitor for reuse from unexpected origins.
Monitor log-aggregation platforms for bulk export, download, or query activity targeting application logs from affected services.
Track file integrity and access on local log paths on hosts running the affected driver.

How to Mitigate CVE-2026-18710

Immediate Actions Required

Upgrade the MongoDB driver to a fixed version as tracked in MongoDB Jira Issue JAVA-6266.
Rotate any credential that the affected driver may have written to logs, including credentials used for outbound network connectivity.
Purge historical log data containing the exposed credential from local storage, backups, and log-aggregation systems.
Restrict read access to application logs and log-aggregation indices to accounts with a documented operational need.

Patch Information

The vendor tracks the fix under MongoDB Jira Issue JAVA-6266. Apply the driver version identified in that ticket. No CPE data is published in NVD at time of writing, so verify the fixed version directly against the vendor issue tracker before deployment.

Workarounds

Lower the driver's log verbosity so that client initialization does not emit configuration data, if the deployed version exposes such a setting.
Apply a log-processing filter in the application or log pipeline that redacts credential fields before persistence.
Isolate log storage on affected hosts with strict filesystem permissions until the driver is upgraded and credentials are rotated.

bash

# Example: redact credential-bearing log lines at the shipper before forwarding
# (Fluent Bit filter stanza, illustrative)
[FILTER]
    Name    modify
    Match   app.*
    Condition Key_value_matches message (?i)(password|credential|authSource)=
    Set     message [REDACTED_BY_POLICY]