CVE-2026-91992: Exposure of Sensitive Information to an Unauthorized Actor in tornadoweb tornado
Tornado versions before 6.5.7 have a vulnerability in CurlAsyncHTTPClient where pycurl handles are reused without clearing sensitive state. This can lead to leakage of credentials such as TLS certificates or proxy authentication data across requests made by the same client instance. The vulnerability allows unauthorized actors to obtain sensitive credentials by issuing requests through the affected client.
AI Analysis
Technical Summary
CVE-2026-91992 is a credential leak vulnerability in Tornado's CurlAsyncHTTPClient prior to version 6.5.7. The issue arises because pycurl handles are reused across multiple requests without properly clearing sensitive state information. As a result, TLS certificates or proxy authentication credentials can persist and be exposed to unauthorized requests made through the same client instance.
Potential Impact
An attacker who can issue requests through the same Tornado CurlAsyncHTTPClient instance may obtain sensitive credentials such as TLS certificates or proxy authentication tokens that should not be accessible. This exposure can compromise confidentiality of sensitive authentication data, potentially allowing unauthorized access to protected resources.
Mitigation Recommendations
Upgrade Tornado to version 6.5.7 or later, where this credential leak vulnerability has been fixed. No other mitigation guidance is provided. Patch status is confirmed by the version boundary in the affectedVersions field.
CVE-2026-91992: Exposure of Sensitive Information to an Unauthorized Actor in tornadoweb tornado
Description
Tornado versions before 6.5.7 have a vulnerability in CurlAsyncHTTPClient where pycurl handles are reused without clearing sensitive state. This can lead to leakage of credentials such as TLS certificates or proxy authentication data across requests made by the same client instance. The vulnerability allows unauthorized actors to obtain sensitive credentials by issuing requests through the affected client.
CVSS v4.0
Score 8.2high
Affected software
tornadoweb
tornado
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-91992 is a credential leak vulnerability in Tornado's CurlAsyncHTTPClient prior to version 6.5.7. The issue arises because pycurl handles are reused across multiple requests without properly clearing sensitive state information. As a result, TLS certificates or proxy authentication credentials can persist and be exposed to unauthorized requests made through the same client instance.
Potential Impact
An attacker who can issue requests through the same Tornado CurlAsyncHTTPClient instance may obtain sensitive credentials such as TLS certificates or proxy authentication tokens that should not be accessible. This exposure can compromise confidentiality of sensitive authentication data, potentially allowing unauthorized access to protected resources.
Mitigation Recommendations
Upgrade Tornado to version 6.5.7 or later, where this credential leak vulnerability has been fixed. No other mitigation guidance is provided. Patch status is confirmed by the version boundary in the affectedVersions field.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-09-15T11:11:13.311Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6aa9652055bf5e2cf502eb46
Added to database: 09/15/2026, 15:32:48 UTC
Last enriched: 09/15/2026, 15:46:26 UTC
Last updated: 09/15/2026, 15:53:15 UTC
Views: 5
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