Medium severity · published Sep 15, 2026
CVE-2026-91992
Tornado before 6.5.7 Credential Leak via Handle Reuse
5.9
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 15% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
TO
tornado · tornadoweb
before 6.5.7 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-91992
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-91992
github.com
https://github.com/tornadoweb/tornado/security/advisories/GHSA-pw6j-qg29-8w7f
www.vulncheck.com
https://www.vulncheck.com/advisories/tornado-before-6.5.7-credential-leak-via-handle-reuse
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