ALAS2-2026-4011


Amazon Linux 2 (EOS) Security Advisory: ALAS2-2026-4011
Advisory Released Date: 2026-10-24
Advisory Updated Date: 2026-10-26
Severity: Important

Issue Overview:

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. (CVE-2026-103262)


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 ALAS2-2026-4011 to update your system.

New Packages:
aarch64:
    python-tornado-4.2.1-3.amzn2.0.9.aarch64
    python-tornado-doc-4.2.1-3.amzn2.0.9.aarch64
    python-tornado-debuginfo-4.2.1-3.amzn2.0.9.aarch64

i686:
    python-tornado-4.2.1-3.amzn2.0.9.i686
    python-tornado-doc-4.2.1-3.amzn2.0.9.i686
    python-tornado-debuginfo-4.2.1-3.amzn2.0.9.i686

src:
    python-tornado-4.2.1-3.amzn2.0.9.src

x86_64:
    python-tornado-4.2.1-3.amzn2.0.9.x86_64
    python-tornado-doc-4.2.1-3.amzn2.0.9.x86_64
    python-tornado-debuginfo-4.2.1-3.amzn2.0.9.x86_64