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LDAP Ingestion Source vulnerable to MITM attack through TLS downgrade

High
RyanHolstien published GHSA-j34h-x7qg-4qw5 Feb 4, 2026

Package

pip metadata-ingestion/src/datahub/ingestion/source/ldap.py (pip)

Affected versions

<1.3.1.8

Patched versions

>=1.3.1.8

Description

Impact

• Vulnerability Type: CWE-295 – Improper Certificate Validation
• Affected Component: metadata-ingestion/src/datahub/ingestion/source/ldap.py

Technical Details
The LDAP ingestion source explicitly weakens TLS certificate validation using the following hardcoded configuration:

ldap.set_option(ldap.OPT_X_TLS_REQUIRE_CERT, ldap.OPT_X_TLS_ALLOW)

The OPT_X_TLS_ALLOW setting accepts TLS connections even when certificate validation fails (including hostname mismatch and untrusted issuers). This allows an attacker to present a rogue certificate and successfully intercept LDAPS credentials.

Additional Severity Factor

The vulnerability is compounded by two issues:

  1. NO CA Certificate Configuration Option Exists

There is no configuration parameter in LDAPSourceConfig to specify a trusted CA certificate file (OPT_X_TLS_CACERTFILE).

  1. OPT_X_TLS_ALLOW Ignores Validation Failures

Even if a CA certificate option were added, the hardcoded OPT_X_TLS_ALLOW setting would ignore validation failures anyway.

Patches

Issue has been fixed in latest codebase.

Workarounds

Ensure DataHub deployment is only exposing necessary external services, this is typically set up on a fully internal network between DataHub and the LDAP deployment and would only be exploitable if the network itself were compromised.

References

https://www.wiz.io/vulnerability-database/cve/cve-2025-12765 Similar issue

Credit

Credit for finding this vulnerability to Arad Inbar, Nir Somech, and Ben Grinberg (DREAM)

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVE ID

CVE-2026-25644

Weaknesses

Improper Certificate Validation

The product does not validate, or incorrectly validates, a certificate. Learn more on MITRE.