ESB-2026.3827
PUBLISHED
CVSS 7.5 HIGH
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AUSCERT External Security Bulletin Redistribution
ESB-2026.3827
nghttp2 security update
17 April 2026
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AUSCERT Security Bulletin Summary
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Product: nghttp2
Publisher: Red Hat
Operating System: Red Hat
Resolution: Patch/Upgrade
CVE Names: CVE-2026-27135
Original Bulletin:
https://access.redhat.com/errata/RHSA-2026:8548
Comment: CVSS (Max): 7.5 CVE-2026-27135 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVSS Source: Red Hat
Calculator: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS (Max): 0.0% (3rd) CVE-2026-27135 2026-04-16
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RHSA-2026:8548 - Security Advisory
Issued: 2026-04-16
Updated: 2026-04-16
Synopsis
Nghttp2 security update
Type/Severity
Security Advisory: Important
Topic
An update for nghttp2 is now available for Red Hat Enterprise Linux 9.6
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):
o 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
o Red Hat Enterprise Linux for x86_64 - Extended Update Support 9.6 x86_64
o Red Hat Enterprise Linux Server - AUS 9.6 x86_64
o Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 9.6
s390x
o Red Hat Enterprise Linux for Power, little endian - Extended Update Support
9.6 ppc64le
o Red Hat Enterprise Linux for ARM 64 - Extended Update Support 9.6 aarch64
o Red Hat Enterprise Linux Server for Power LE - Update Services for SAP
Solutions 9.6 ppc64le
o Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.6
x86_64
o Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support 9.6
x86_64
o Red Hat CodeReady Linux Builder for Power, little endian - Extended Update
Support 9.6 ppc64le
o Red Hat CodeReady Linux Builder for IBM z Systems - Extended Update Support
9.6 s390x
o Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support 9.6
aarch64
o Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.6 aarch64
o Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.6 s390x
o Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.6 x86_64
o Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.6 aarch64
o Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.6
ppc64le
o Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.6 s390x
Fixes
o BZ - 2448754 - CVE-2026-27135 nghttp2: nghttp2: Denial of Service via
malformed HTTP/2 frames after session termination
CVEs
o CVE-2026-27135
References
o https://access.redhat.com/security/updates/classification/#important
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