RHSA-2026:83618 - Security Advisory

Topic

An update for libsoup3 is now available for Red Hat Enterprise Linux 10.

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

Libsoup is an HTTP library implementation in C. It was originally part of a SOAP (Simple Object Access Protocol) implementation called Soup, but the SOAP and non-SOAP parts have now been split into separate packages. libsoup uses the Glib main loop and is designed to work well with GTK applications. This enables GNOME applications to access HTTP servers on the network in a completely asynchronous fashion, very similar to the Gtk+ programming model (a synchronous operation mode is also supported for those who want it), but the SOAP parts were removed long ago.

Security Fix(es):

• libsoup: libsoup: Heap buffer overflow via uninitialized length in data-URI base64 decoding (CVE-2026-102555)
• libsoup: libsoup: Heap buffer overflow from WebSocket Pong signal type confusion (CVE-2026-102556)
• libsoup: libsoup: Heap buffer overflow during WebSocket message reassembly (CVE-2026-102557)
• libsoup: libsoup: Heap buffer overflow during WebSocket receive-buffer growth (CVE-2026-102558)
• libsoup: libsoup: Heap buffer overflow during WebSocket client-frame masking (CVE-2026-102559)
• libsoup: libsoup: Heap buffer overflow during outgoing permessage-deflate buffer growth (CVE-2026-102560)

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 10 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 10.2 x86_64
• Red Hat Enterprise Linux for IBM z Systems 10 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 10.2 s390x
• Red Hat Enterprise Linux for Power, little endian 10 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 10.2 ppc64le
• Red Hat Enterprise Linux for ARM 64 10 aarch64
• Red Hat Enterprise Linux for ARM 64 - Extended Update Support 10.2 aarch64
• Red Hat CodeReady Linux Builder for x86_64 10 x86_64
• Red Hat CodeReady Linux Builder for Power, little endian 10 ppc64le
• Red Hat CodeReady Linux Builder for ARM 64 10 aarch64
• Red Hat CodeReady Linux Builder for IBM z Systems 10 s390x
• Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support 10.2 x86_64
• Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support 10.2 ppc64le
• Red Hat CodeReady Linux Builder for IBM z Systems - Extended Update Support 10.2 s390x
• Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support 10.2 aarch64
• Red Hat Enterprise Linux for ARM 64 - 4 years of updates 10.2 aarch64
• Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 10.2 s390x
• Red Hat Enterprise Linux for Power, little endian - 4 years of support 10.2 ppc64le
• Red Hat Enterprise Linux for x86_64 - 4 years of updates 10.2 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 10.2 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 10.2 aarch64
• Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 10.2 ppc64le
• Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 10.2 s390x

Fixes

• BZ - 2543224 - CVE-2026-102555 libsoup: libsoup: Heap buffer overflow via uninitialized length in data-URI base64 decoding
• BZ - 2543229 - CVE-2026-102556 libsoup: libsoup: Heap buffer overflow from WebSocket Pong signal type confusion
• BZ - 2543231 - CVE-2026-102557 libsoup: libsoup: Heap buffer overflow during WebSocket message reassembly
• BZ - 2543274 - CVE-2026-102558 libsoup: libsoup: Heap buffer overflow during WebSocket receive-buffer growth
• BZ - 2543285 - CVE-2026-102559 libsoup: libsoup: Heap buffer overflow during WebSocket client-frame masking
• BZ - 2543296 - CVE-2026-102560 libsoup: libsoup: Heap buffer overflow during outgoing permessage-deflate buffer growth

CVEs

• CVE-2026-102555
• CVE-2026-102556
• CVE-2026-102557
• CVE-2026-102558
• CVE-2026-102559
• CVE-2026-102560

References

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