Amazon Linux 2 (EOS) Security Advisory: ALAS2-2026-3976
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:
python-tornado
Note:
This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.
Issue Correction:
Run yum update python-tornado or yum update --advisory ALAS2-2026-3976 to update your system.
New Packages:
aarch64:
python-tornado-4.2.1-3.amzn2.0.8.aarch64
python-tornado-doc-4.2.1-3.amzn2.0.8.aarch64
python-tornado-debuginfo-4.2.1-3.amzn2.0.8.aarch64
i686:
python-tornado-4.2.1-3.amzn2.0.8.i686
python-tornado-doc-4.2.1-3.amzn2.0.8.i686
python-tornado-debuginfo-4.2.1-3.amzn2.0.8.i686
src:
python-tornado-4.2.1-3.amzn2.0.8.src
x86_64:
python-tornado-4.2.1-3.amzn2.0.8.x86_64
python-tornado-doc-4.2.1-3.amzn2.0.8.x86_64
python-tornado-debuginfo-4.2.1-3.amzn2.0.8.x86_64