CVE-2026-126837

Attacker able to redirect a client's database traffic to a host they control via special characters in an SRV target, bypassing the SRV parent-domain guard

Published Nov 12, 2026 CVSS 4.0 · 9.1 Critical EPSS < 1% KEV · Not listed
Description
A validation flaw in the DNS SRV host discovery of the MongoDB Node.js driver may cause the driver to connect to a host outside the expected domain. For a mongodb+srv:// connection string, the driver checks each host name in the DNS SRV response against the domain of the connection string. The driver then builds the connection address from the original name, in which certain characters end the host name early. An unauthenticated party who can forge or change the DNS SRV response may redirect the connection to a host of their choice. TLS does not prevent this, because the driver verifies the server certificate against the redirected host name. This may result in unintended disclosure of application data and authentication credentials, and in altered query results. Applications that use mongodb:// connection strings are not affected.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

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References
History
Type Values Removed Values Added
Weaknesses CWE-88
Type Values Removed Values Added
Weaknesses CWE-180
Type Values Removed Values Added
Description A validation flaw in the DNS SRV host discovery of the MongoDB Node.js driver may cause the driver to connect to a host outside the expected domain. For a mongodb+srv:// connection string, the driver checks each host name in the DNS SRV response against the domain of the connection string. The driver then builds the connection address from the original name, in which certain characters end the host name early. An unauthenticated party who can forge or change the DNS SRV response may redirect the connection to a host of their choice. TLS does not prevent this, because the driver verifies the server certificate against the redirected host name. This may result in unintended disclosure of application data and authentication credentials, and in altered query results. Applications that use mongodb:// connection strings are not affected.
Title Attacker able to redirect a client's database traffic to a host they control via special characters in an SRV target, bypassing the SRV parent-domain guard
Weaknesses CWE-88
References
Metrics cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'}

cvssV4_0

{'score': 9.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N'}

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Weaknesses

Sources

Status
PUBLISHED
Assigner
mongodb
Published
Updated
Nov 12, 2026, 5:31 PM
Reserved
Nov 11, 2026, 9:48 PM
Status
Awaiting Analysis
Published
Nov 12, 2026, 5:17 PM
Modified
Nov 12, 2026, 10:09 PM