# CVE-2026-91992: python3-tornado: Tornado before 6.5.7 contains a credential leak vulnerability in CurlAsyncHTTPClient where pycurl handles are reused...

CVE-2026-91992 is fixed in 2 products on 1 platform, first by python3-tornado 6.5.4-0.1ubuntu0.2, released October 1, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-91992
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0024
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 15, 2026

## Description

Tornado before 6.5.7 contains a credential leak vulnerability in CurlAsyncHTTPClient where pycurl handles are reused across requests without proper state clearing. Attackers can obtain sensitive credentials by issuing requests through the same client instance, allowing TLS certificates or proxy authentication to persist across unintended requests.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | python-tornado Ubuntu 18.04.6 LTS (bionic) | 4.5.3-1ubuntu0.2+esm4 | [python-tornado 4.5.3-1ubuntu0.2+esm4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python-tornado-4.5.3-1ubuntu0.2-esm4.md) | Oct 24, 2026 |
| Linux | python3-tornado Ubuntu 18.04.6 LTS (bionic) | 4.5.3-1ubuntu0.2+esm4 | [python3-tornado 4.5.3-1ubuntu0.2+esm4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python3-tornado-4.5.3-1ubuntu0.2-esm4.md) | Oct 24, 2026 |
| Linux | python3-tornado Ubuntu 22.04.1 LTS (jammy) | 6.1.0-3ubuntu0.1~esm6 | [python3-tornado 6.1.0-3ubuntu0.1~esm6](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-python3-tornado-6.1.0-3ubuntu0.1-esm6.md) | Oct 24, 2026 |
| Linux | python3-tornado Ubuntu 24.04.5 LTS (noble) | 6.4.0-1ubuntu0.6 | [python3-tornado 6.4.0-1ubuntu0.6](https://patchblox.com/security/data/fix/linux/ubuntu-noble-python3-tornado-6.4.0-1ubuntu0.6.md) | Oct 24, 2026 |
| Linux | python3-tornado Ubuntu 26.04.1 LTS (resolute) | 6.5.4-0.1ubuntu0.2 | [python3-tornado 6.5.4-0.1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-python3-tornado-6.5.4-0.1ubuntu0.2.md) | Oct 1, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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