Amazon Linux 2023 Security Advisory: ALAS2023-2026-3093
Advisory Released Date: 2026-09-29
Advisory Updated Date: 2026-09-29
Severity:
Important
Issue Overview:
Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.8, Tornado parses application/x-www-form-urlencoded request bodies with urllib.parse.parse_qs in tornado/escape.py without passing max_num_fields. RequestHandler._execute in tornado/web.py parses the body before handler dispatch through HTTPServerRequest._parse_body and parse_body_arguments in tornado/httputil.py, so an unauthenticated request body containing millions of separator-delimited fields can synchronously stall the single-threaded event loop and delay every connection. The body is bounded only by max_buffer_size, which defaults to 104857600 bytes. This issue is fixed in version 6.5.8. (CVE-2026-82397)
Affected Packages:
python-tornado
Issue Correction:
Run dnf update python-tornado --releasever 2023.12.20260928 or dnf update --advisory ALAS2023-2026-3093 --releasever 2023.12.20260928 to update your system.
More information on how to update your system can be found on this page: Amazon Linux 2023 documentation
New Packages:
aarch64:
python3-tornado-debuginfo-6.1.0-2.amzn2023.0.10.aarch64
python-tornado-debugsource-6.1.0-2.amzn2023.0.10.aarch64
python-tornado-doc-6.1.0-2.amzn2023.0.10.aarch64
python3-tornado-6.1.0-2.amzn2023.0.10.aarch64
src:
python-tornado-6.1.0-2.amzn2023.0.10.src
x86_64:
python-tornado-debugsource-6.1.0-2.amzn2023.0.10.x86_64
python3-tornado-debuginfo-6.1.0-2.amzn2023.0.10.x86_64
python-tornado-doc-6.1.0-2.amzn2023.0.10.x86_64
python3-tornado-6.1.0-2.amzn2023.0.10.x86_64