RHSA-2026:98107 - Security Advisory

Topic

An update for python-tornado is now available for Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems.

Security Fix(es):

• tornado: Tornado: Denial of Service via uncontrolled gzip decompression memory consumption (CVE-2026-49855)
• python-tornado: Tornado: Denial of Service via excessive URL-encoded body fields (CVE-2026-82397)
• tornado: Tornado: Denial of Service via memory amplification in multipart parsing (CVE-2026-91990)
• tornado: Tornado: Denial of Service via decompression bomb in CurlAsyncHTTPClient (CVE-2026-103262)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Server - AUS 9.4 x86_64
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.4 ppc64le
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.4 x86_64
• Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.4 aarch64
• Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.4 s390x
• Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.4 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.4 aarch64
• Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.4 ppc64le
• Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.4 s390x

Fixes

• BZ - 2500686 - CVE-2026-49855 tornado: Tornado: Denial of Service via uncontrolled gzip decompression memory consumption
• BZ - 2526562 - CVE-2026-82397 python-tornado: Tornado: Denial of Service via excessive URL-encoded body fields
• BZ - 2533953 - CVE-2026-91990 tornado: Tornado: Denial of Service via memory amplification in multipart parsing
• BZ - 2544534 - CVE-2026-103262 tornado: Tornado: Denial of Service via decompression bomb in CurlAsyncHTTPClient

CVEs

• CVE-2026-49855
• CVE-2026-82397
• CVE-2026-91990
• CVE-2026-103262

References

• https://access.redhat.com/security/updates/classification/#important