Information disclosure in Tornadoweb Tornado
CVE-2026-49853
Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.6, SimpleAsyncHTTPClient shallow-copied redirected requests and removed only the Host header, leaving Authorization, auth_username, auth_password, and auth_mode in place when a redirect changed scheme, host, or port. This issue is fixed in version 6.5.6.
Vulnerability class: Information Disclosure
EPSS: 0.004 (29.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N.
Affected products
- Tornadoweb Tornado — versions < 6.5.6
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-49853?
- CVE-2026-49853 is a high-severity vulnerability in Tornadoweb Tornado, classified under Information Disclosure. CVSS score: 7.7/10. Published 2026-07-14.
- How severe is CVE-2026-49853?
- High severity. CVSS v3 base score is 7.7 out of 10.