CVE-2026-15709 Soupwebsocketextensiondeflate: libsoup: libsoup: websocket permessage-deflate unbounded decompression remote denial of service
Description
A flaw was found in libsoup's WebSocket implementation when using the permessage-deflate extension. The extension's decompression loop (inflate()) processes data in chunks without enforcing an upper boundary limit on the output buffer size. While libsoup limits the incoming compressed frame size via max_incoming_payload_size, it fails to track or limit memory allocation during decompression. A separate check for decompressed size (max_total_message_size) exists but executes only after inflation is complete, and it is entirely disabled by default for client connections. A remote, unauthenticated attacker can exploit this by sending a small, highly compressed payload (a decompression bomb), causing unbounded memory allocation that triggers an Out-of-Memory (OOM) crash and a Denial of Service (DoS).
CVSS 3.1 detail
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitable remotely over the network, without an account and without any user action; an attacker can seriously compromise confidentiality, integrity or availability.
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- Interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Red Hat Enterprise Linux 10 | Versions not published | |
| Red Hat Enterprise Linux 6 | Versions not published | |
| Red Hat Enterprise Linux 7 | Versions not published | |
| Red Hat Enterprise Linux 8 | Versions not published | |
| Red Hat Enterprise Linux 9 | Versions not published | |
| Red Hat Enterprise Linux 9.6 Extended Update Support | Versions not published | |
| Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions | Versions not published | |
| Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions | Versions not published | |
| Red Hat Enterprise Linux 8.8 Telecommunications Update Service | Versions not published |
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| Product | Affected versions | Fixed in |
|---|---|---|
| Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions | Versions not published | |
| Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | Versions not published | |
| Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On | Versions not published | |
| Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | Versions not published | |
| Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On | Versions not published | |
| Red Hat Enterprise Linux 10.0 Extended Update Support | Versions not published |
References
- RHSA-2026:68234 access.redhat.com
- RHSA-2026:68235 access.redhat.com
- RHSA-2026:68612 access.redhat.com
- RHSA-2026:69108 access.redhat.com
- RHSA-2026:69297 access.redhat.com
- RHSA-2026:69863 access.redhat.com
- RHSA-2026:70598 access.redhat.com
- RHSA-2026:70599 access.redhat.com
- RHSA-2026:71389 access.redhat.com
- access.redhat.com access.redhat.com
- RHBZ#2499922 bugzilla.redhat.com
- gitlab.gnome.org gitlab.gnome.org
Timeline
- Published
- Last modified