RHSA-2026:8547 - Security Advisory

Topic

An update for nghttp2 is now available for Red Hat Enterprise Linux 9.4 Extended Update Support.

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

libnghttp2 is a library implementing the Hypertext Transfer Protocol version 2 (HTTP/2) protocol in C.

Security Fix(es):

• nghttp2: nghttp2: Denial of Service via malformed HTTP/2 frames after session termination (CVE-2026-27135)

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 for x86_64 - Extended Update Support 9.4 x86_64
• Red Hat Enterprise Linux Server - AUS 9.4 x86_64
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 9.4 s390x
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 9.4 ppc64le
• Red Hat Enterprise Linux for ARM 64 - Extended Update Support 9.4 aarch64
• 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 CodeReady Linux Builder for x86_64 - Extended Update Support 9.4 x86_64
• Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support 9.4 ppc64le
• Red Hat CodeReady Linux Builder for IBM z Systems - Extended Update Support 9.4 s390x
• Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support 9.4 aarch64
• 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 - 2448754 - CVE-2026-27135 nghttp2: nghttp2: Denial of Service via malformed HTTP/2 frames after session termination

CVEs

• CVE-2026-27135

References

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