Information disclosure in Tornadoweb Tornado
CVE-2026-91992
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.
Vulnerability class: Information Disclosure
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.002 (15.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 15th percentile — 15.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.002 · change: -0.000
Affected products
Weakness classification (CWE)
References
- github.com/tornadoweb/tornado/security/advisories/GHSA-pw6j-qg29-8w7f (vendor-advisory)
- www.vulncheck.com/advisories/tornado-before-6.5.7-credential-leak-via-handle-re… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-91992?
- CVE-2026-91992 is a medium-severity vulnerability in Tornadoweb Tornado, classified under Information Disclosure. CVSS score: 5.9/10. Published 2026-09-15.
- How severe is CVE-2026-91992?
- Medium severity. CVSS v3 base score is 5.9 out of 10.