RHSA-2026:70599 - Security Advisory

Topic

An update for libsoup is now available for Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On.

Red Hat Product Security has rated this update as having a security impact of Moderate. 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

The libsoup packages provide an HTTP client and server library for GNOME.

Security Fix(es):

• SoupWebsocketExtensionDeflate: libsoup: libsoup: WebSocket permessage-deflate Unbounded Decompression Remote Denial of Service (CVE-2026-15709)
• libsoup: SoupWebsocketConnection: libsoup: WebSocket remote denial of service via oversized control frame protocol violation (CVE-2026-15711)

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 Life Cycle Long Life 8.4 x86_64
• Red Hat Enterprise Linux Server - AUS 8.4 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle Long Life 8.4 aarch64
• Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle Long Life 8.4 ppc64le
• Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle Long Life 8.4 s390x

Fixes

• BZ - 2499922 - CVE-2026-15709 SoupWebsocketExtensionDeflate: libsoup: libsoup: WebSocket permessage-deflate Unbounded Decompression Remote Denial of Service
• BZ - 2499924 - CVE-2026-15711 libsoup: SoupWebsocketConnection: libsoup: WebSocket remote denial of service via oversized control frame protocol violation

CVEs

• CVE-2026-15709
• CVE-2026-15711

References

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