Name: CVE-2026-103262: Improper Handling of Highly Compressed Data (Data Amplification)
Creator: Rapid7
Published: 2026-10-01T00:00:00.000Z
License: https://www.rapid7.com/legal/website-terms-of-use/
Keywords: CVE, CVE-2026-103262, CWE-409, CVSS 7.5, EPSS 0.00525

Tornado versions before 6.5.9 contain an unbounded memory accumulation vulnerability in CurlAsyncHTTPClient that allows remote attackers to cause denial of service by sending a compressed response. Attackers can send a gzip-encoded decompression bomb that accumulates in memory without size limits, causing the application process to be killed by out-of-memory conditions.

CVSS Details

CVSS 4.0 Base Score: 8.7 (HIGH)
CVSS 4.0 Vector: (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X)
CVSS 3.1 Base Score: 7.5
CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

Covered by Rapid7

Product	Vendor Advisory	Solution File	Added	Published
Alma_linux	—	Upgrade python3-tornado	Oct 14, 2026	Oct 13, 2026
Oracle_linux	—	Upgrade python3-tornado	Oct 22, 2026	Oct 1, 2026
Redhat_linux	—	Upgrade python-tornado-debugsourceUpgrade python3-tornado-debuginfoUpgrade python3-tornado	Oct 5, 2026	Oct 1, 2026
Rocky_linux	—	Upgrade python3-tornado-debuginfoUpgrade python-tornado-debugsourceUpgrade python3-tornado	Oct 16, 2026	Oct 14, 2026
Ubuntu	—	Upgrade python-tornado (Ubuntu Pro)Upgrade python-tornado	Oct 22, 2026	Oct 1, 2026

Prioritize with Active Threat Intelligence

With curated Threat Intelligence, you can see which vulnerabilities truly put you at risk, prioritize what matters most, and act before attackers do.

Explore Intelligence Hub

MDR Buyer's Guide

Global Threat Landscape Report

Grow your business

CVSS Details

Covered by Rapid7

Prioritize with Active Threat Intelligence