Vulnerability 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.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/tornadoweb/tornado/commit/ff808b33adc52d89a549376a5e3628e92ab
- https://github.com/tornadoweb/tornado/pull/3626
- https://github.com/tornadoweb/tornado/security/advisories/GHSA-mgf9-4vpg-hj56
FAQ
What is CVE-2026-49855?
CVE-2026-49855 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 accumul...
How severe is CVE-2026-49855?
CVE-2026-49855 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-49855?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.