CVE-2026-91992

Tornado before 6.5.7 Credential Leak via Handle Reuse

At a glance

Severity: HIGH 8.2
EPSS: EPSS 0.24 % · percentile 15 (2026-10-27)
State: PUBLISHED
Published: 2026-09-15
Updated: 2026-09-17
Assigner: VulnCheck
NVD status: Deferred

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.

Scores

Version	Score	Vector	Scored by
CVSS 4.0	HIGH 8.2	CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N	VulnCheck
CVSS 3.1	MEDIUM 5.9	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N	VulnCheck
CVSS 4.0	HIGH 8.2	CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X	NVD · disclosure@vulncheck.com (Secondary)
CVSS 3.1	MEDIUM 5.9	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N	NVD · disclosure@vulncheck.com (Secondary)

Weaknesses (CWE)

CWE-200

Advisories

GHSA-pw6j-qg29-8w7f — Tornado: CurlAsyncHTTPClient leaks per-request credentials on handle reuse

European references

ENISA EUVD · EUVD-2026-78664
GCVE · GCVE-0-2026-91992

Affected products

Product	Versions
tornadoweb · tornado	affected 0 < 6.5.7 ; unaffected 6.5.7

References

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
EPSS (FIRST.org)	FIRST — attribution requested
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD