CVE-2026-49855

Published: Jul 14, 2026Modified: Jul 16, 2026Deferred

7.5

Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploitability: 3.9 / Impact: 3.6

Source: security-advisories@github.com (Secondary)

Description

Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.6, Tornado gzip decompression routines processed limited-size chunks but did not enforce an overall limit on accumulated decompressed chunks, allowing a malicious server accessed by SimpleAsyncHTTPClient or an HTTPServer configured with decompress_request=True to consume effectively unlimited memory. This issue is fixed in version 6.5.6.

Related CWEs

CWE-409

Improper Handling of Highly Compressed Data (Data Amplification)

The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output.

References (3)

https://github.com/tornadoweb/tornado/commit/ff808b33adc52d89a549376a5e3628e92abbc8ff

Source: security-advisories@github.com

https://github.com/tornadoweb/tornado/pull/3626

Source: security-advisories@github.com

https://github.com/tornadoweb/tornado/security/advisories/GHSA-mgf9-4vpg-hj56

Source: security-advisories@github.com

Timeline

No history available yet.