CVE-2026-35561 Overview
CVE-2026-35561 is an Authentication Bypass vulnerability affecting the browser-based authentication components in the Amazon Athena ODBC driver versions prior to 2.1.0.0. The vulnerability stems from insufficient authentication security controls that could allow a threat actor to intercept or hijack authentication sessions due to inadequate protections in the browser-based authentication flows.
This vulnerability is classified under CWE-862 (Missing Authorization), indicating a fundamental flaw in how the driver validates and protects authentication sessions during browser-based authentication workflows.
Critical Impact
A remote, unauthenticated attacker could intercept or hijack authentication sessions, potentially gaining unauthorized access to Amazon Athena resources and sensitive data through compromised credentials.
Affected Products
- Amazon Athena ODBC Driver versions before 2.1.0.0 (Windows)
- Amazon Athena ODBC Driver versions before 2.1.0.0 (Linux)
- Amazon Athena ODBC Driver versions before 2.1.0.0 (macOS Intel and ARM)
Discovery Timeline
- 2026-04-03 - CVE-2026-35561 published to NVD
- 2026-04-07 - Last updated in NVD database
Technical Details for CVE-2026-35561
Vulnerability Analysis
The vulnerability exists within the browser-based authentication components of the Amazon Athena ODBC driver. When users authenticate through browser-based flows (such as SAML or OAuth), the driver fails to implement sufficient security controls to protect the authentication session from interception or manipulation.
The root cause relates to CWE-862 (Missing Authorization), where the authentication flow lacks proper validation mechanisms to ensure that authentication responses are legitimately bound to the originating authentication request. This creates an opportunity for attackers positioned on the network to intercept authentication tokens or hijack active sessions.
The network-based attack vector makes this particularly concerning for organizations using the Athena ODBC driver in shared network environments or where network segmentation is insufficient.
Root Cause
The vulnerability originates from insufficient protections in the browser-based authentication implementation. Specifically, the authentication flow lacks adequate session binding, token validation, or secure channel protections that would prevent an attacker from intercepting or replaying authentication credentials. This missing authorization check (CWE-862) allows unauthorized parties to potentially capture and reuse authentication tokens intended for legitimate users.
Attack Vector
The attack can be conducted remotely over the network without requiring prior authentication or user interaction. An attacker with network access between the victim and the authentication endpoint could:
- Monitor network traffic for browser-based authentication flows initiated by the Athena ODBC driver
- Intercept authentication tokens or session identifiers during the authentication process
- Hijack the authentication session to gain unauthorized access to Amazon Athena resources
- Potentially access or manipulate data within the victim's Athena environment
The vulnerability mechanism involves insufficient validation during the browser-based authentication handshake, where authentication responses may not be properly bound to the original request or adequately protected during transit. For detailed technical information, refer to the AWS Security Bulletin 2026-013.
Detection Methods for CVE-2026-35561
Indicators of Compromise
- Unexpected authentication sessions or token requests originating from unfamiliar IP addresses or network locations
- Multiple authentication attempts for the same user from different network segments within short time windows
- Anomalous Athena query activity following browser-based authentication events
- Presence of Amazon Athena ODBC driver versions prior to 2.1.0.0 in software inventory
Detection Strategies
- Implement network traffic analysis to identify suspicious patterns in ODBC driver authentication flows
- Monitor AWS CloudTrail logs for unusual Athena access patterns or authentication anomalies
- Deploy endpoint detection rules to identify vulnerable driver versions (< 2.1.0.0) across the organization
- Configure alerting for authentication session anomalies such as session reuse from different source IPs
Monitoring Recommendations
- Enable detailed logging for Amazon Athena access and authentication events in AWS CloudTrail
- Implement network segmentation monitoring to detect potential man-in-the-middle positioning
- Establish baseline authentication behavior for Athena ODBC connections and alert on deviations
- Review AWS security findings and GuardDuty alerts related to Athena service access
How to Mitigate CVE-2026-35561
Immediate Actions Required
- Upgrade the Amazon Athena ODBC driver to version 2.1.0.0 or later immediately on all affected systems
- Audit all systems using the Athena ODBC driver to identify vulnerable installations
- Review Athena access logs for any signs of unauthorized access that may have occurred prior to patching
- Consider temporarily disabling browser-based authentication methods until the upgrade is complete
Patch Information
Amazon has released version 2.1.0.0 of the Athena ODBC driver to address this vulnerability. The patched driver is available for download from the following official sources:
- Windows: Amazon Athena ODBC Driver Windows
- Linux (RPM): Amazon Athena ODBC Driver RPM
- macOS Intel: Amazon Athena ODBC Driver Mac Intel
- macOS ARM: Amazon Athena ODBC Driver Mac ARM
For complete release notes and additional details, see the AWS ODBC Driver Release Notes.
Workarounds
- Use alternative authentication methods (such as IAM credentials or instance profiles) instead of browser-based authentication until patching is complete
- Implement strict network segmentation to isolate systems using the Athena ODBC driver from untrusted network segments
- Enable TLS inspection and monitoring on network paths used for Athena ODBC authentication
- Restrict Athena access to specific IP ranges using IAM policies as an additional layer of protection
# Verify installed driver version on Linux
rpm -qa | grep -i athena
# Update driver on Linux (RPM-based systems)
sudo rpm -Uvh AmazonAthenaODBC-2.1.0.0.rpm
# Verify successful upgrade
rpm -qa | grep -i athena
# Expected output: AmazonAthenaODBC-2.1.0.0
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
