CVE-2026-49853: high-severity vulnerability in tornadoweb tornado
Tornado: Authorization header forwarded across cross-origin redirects in SimpleAsyncHTTPClient
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.7epss 0.4%
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.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
Affected products
tornadoweb · tornadoRelated CVEs — tornadoweb tornado
In the same product, most dangerous first.
CVE-2024-52804HIGHTornado has HTTP cookie parsing DoS vulnerabilityEPSS 1.0%CVE-2025-47287HIGHTornado vulnerable to excessive logging caused by malformed multipart form dataEPSS 0.7%CVE-2026-103262HIGHTornado before 6.5.9 Denial of Service via CurlAsyncHTTPClientEPSS 0.6%CVE-2026-49855HIGHtornado AsyncHTTPClient accumulates decompressed chunks without size limit (gzip bomb)EPSS 0.6%CVE-2025-67725HIGHTornado is Vulnerable to Quadratic DoS via Repeated Header CoalescingEPSS 0.6%CVE-2025-67726HIGHTornado is Vulnerable to Quadratic DoS via Crafted Multipart ParametersEPSS 0.5%