ALSA-2026:83618
Important: libsoup3 security update
Published Oct 15, 2026 · corrected/updated Oct 16, 2026 · evidence confidence medium
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.
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
ALSA-2026:83618 is a unknown public vulnerability record for this product. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether this product is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: libsoup3 (0 → 3.6.5-3.el10_2.20); libsoup3-devel (0 → 3.6.5-3.el10_2.20); libsoup3-doc (0 → 3.6.5-3.el10_2.20). Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: no CVSS/EPSS yet. It is not currently listed in the CISA Known Exploited catalog. Sources contributing to this record: osv. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Not listed as known exploited in CISA KEV. Not in the CISA KEV catalog.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Oct 15, 2026 · OSV.dev
Detected
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
Oct 16, 2026 · OSV.dev
Fix available
libsoup3 fixed in 3.6.5-3.el10_2.20; libsoup3-devel fixed in 3.6.5-3.el10_2.20; libsoup3-doc fixed in 3.6.5-3.el10_2.20
Oct 16, 2026 · OSV.dev
Fix available
libsoup3 fixed in 3.6.5-3.el10_2.20
Oct 16, 2026 · OSV.dev
Fix available
libsoup3-devel fixed in 3.6.5-3.el10_2.20
Oct 16, 2026 · OSV.dev
Fix available
libsoup3-doc fixed in 3.6.5-3.el10_2.20
Oct 16, 2026 · OSV.dev
Updated
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
Affected
- AlmaLinux:10 libsoup30 → 3.6.5-3.el10_2.20
- AlmaLinux:10 libsoup3-devel0 → 3.6.5-3.el10_2.20
- AlmaLinux:10 libsoup3-doc0 → 3.6.5-3.el10_2.20