CVE-2026-49855 — tornado AsyncHTTPClient accumulates decompressed chunks without size limit (gzip bomb)
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 o…
Published: 2026-07-14 · CVSS: 7.5 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7