RLSA-2026:98560

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):

• 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)

• libsoup: libsoup: Heap use-after-free in libsoup HTTP/2 client on_data_read() via GOAWAY during body upload (CVE-2026-85197)

• 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.