CVE-2026-85525

Improper OCSP validation lets revoked TLS certs be accepted, enabling MITM reads.

• CVSS 7.4
• 295
• Authentication, Authorization, and Session Management
• Remote

Improper OCSP response validation in the Snowflake Python, Go, JDBC, and Node.js drivers allowed a revoked TLS certificate to be accepted as valid, because OCSP responses were not reliably bound to the certificate being validated and definitive verification failures were treated as transient. A man-in-the-middle attacker holding a revoked certificate and its private key for a Snowflake or stage hostname could cause the driver to establish a TLS session to the attacker-controlled endpoint anyway, allowing the attacker to read and modify data transmitted within that connection. Successful exploitation requires that on-path position and the corresponding private key, and impact is limited to data carried within the intercepted connection. The fix is available in Snowflake Connector for Python v4.7.3, Snowflake Go Driver v2.2.0, Snowflake JDBC Driver v4.3.4 (including the snowflake-jdbc-fips and snowflake-jdbc-thin), and Snowflake Node.js Driver v3.3.0. Users must manually upgrade.

CVE

CVE-2026-85525

CWE

295

CVSS base score

7.4

Published

2026-09-04

OWASP

A02 Cryptographic Failures

Orthogonal defect classification

Checking

Code defect classification

Incorrect Check

Category

Authentication, Authorization, and Session Management

Subcategory

Insecure Authentication Mechanisms

Accessibility scope

Remote

Impact

Information Disclosure

Fixed by upgrading

Yes

Solution

Upgrade to the patched versions: Python connector v4.7.3, Go driver v2.2.0, JDBC driver v4.3.4 (including snowflake‑jdbc‑fips and snowflake‑jdbc‑thin), and Node.js driver v3.3.0.

import snowflake.connector

def get_connection():
    # VULNERABLE: OCSP failures are treated as transient and ignored
    ctx = snowflake.connector.connect(
        user='user',
        password='pwd',
        account='myaccount',
        ocsp_fail_open=True  # allows revoked certs to be accepted
    )
    return ctx

import snowflake.connector

def get_connection():
    # FIX: Reject OCSP failures to enforce proper certificate validation
    ctx = snowflake.connector.connect(
        user='user',
        password='pwd',
        account='myaccount',
        ocsp_fail_open=False  # ensures revoked certs are rejected
    )
    return ctx

@misc{vaitp:cve202685525,
  title        = {{Improper OCSP validation lets revoked TLS certs be accepted, enabling MITM reads.}},
  author       = {Bogaerts, Fr\'ed\'eric and Ivaki, Naghmeh and Fonseca, Jos\'e},
  year         = {2026},
  note         = {VAITP Python Vulnerability Dataset, entry CVE-2026-85525},
  howpublished = {\url{https://netpack.pt/vaitp/vulnerability/CVE-2026-85525/}}
}