Amazon Linux 2023 Security Advisory: ALAS2023-2026-3176
Advisory Released Date: 2026-10-12
Advisory Updated Date: 2026-10-12
Severity:
Important
Issue Overview:
Tornado before 6.5.8 contains a memory amplification vulnerability in parse_multipart_form_data that splits multipart data before validating the max_parts limit. Attackers can send crafted multipart requests with many parts to create large transient lists, exhausting server memory and causing denial of service. (CVE-2026-91990)
Affected Packages:
python3.13-tornado
Issue Correction:
Run dnf update python3.13-tornado --releasever 2023.12.20261012 or dnf update --advisory ALAS2023-2026-3176 --releasever 2023.12.20261012 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:
python3.13-tornado-debugsource-6.4.2-1.amzn2023.0.6.aarch64
python3.13-tornado-debuginfo-6.4.2-1.amzn2023.0.6.aarch64
python3.13-tornado-doc-6.4.2-1.amzn2023.0.6.aarch64
python3.13-tornado-6.4.2-1.amzn2023.0.6.aarch64
src:
python3.13-tornado-6.4.2-1.amzn2023.0.6.src
x86_64:
python3.13-tornado-debugsource-6.4.2-1.amzn2023.0.6.x86_64
python3.13-tornado-debuginfo-6.4.2-1.amzn2023.0.6.x86_64
python3.13-tornado-doc-6.4.2-1.amzn2023.0.6.x86_64
python3.13-tornado-6.4.2-1.amzn2023.0.6.x86_64