VDB
CVE-2026-49855
CVE-2026-49855
PUBLISHED
CVSS 7.5 HIGH
Reported by GitHub_M · Published July 14, 2026
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.
Risk Scores
CVSS 3.1
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| tornadoweb | tornado | < 6.5.6 |
| chainguard | mitmproxy | 0, 0, 0 |
| tornadoweb | tornado | < 6.5.6, < 6.5.6 |
| wolfi | mitmproxy | 0, 0, 0 |
Timeline
- Jun 13, 2026 CVE Published
- Jul 15, 2026 Coalition ESS Score
- Jul 15, 2026 Security Advisory
- Jul 16, 2026 CVE Updated
- Aug 7, 2026 EPSS Score
- Aug 24, 2026 EPSS Score
- Aug 26, 2026 EPSS Score
- Aug 28, 2026 EPSS Score
- Aug 30, 2026 EPSS Score
- Sep 3, 2026 EPSS Score
- Sep 5, 2026 EPSS Score
- Sep 6, 2026 EPSS Score
References
- https://github.com/tornadoweb/tornado/security/advisories/GHSA-mgf9-4vpg-hj56 x_refsource_CONFIRM
- https://github.com/tornadoweb/tornado/pull/3626 x_refsource_MISC
- https://github.com/tornadoweb/tornado/commit/ff808b33adc52d89a549376a5e3628e92abbc8ff x_refsource_MISC