EUVD-2026-51528
GHSA-5hp4-5mvq-qw3w
Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Unauthenticated network flood in the pre-auth accept path (AV:N/AC:L/PR:N/UI:N) causing pure availability loss with no confidentiality or integrity impact (C:N/I:N/A:H).
Primary rating from Vendor (redhat).
CVSS VectorVendor: redhat
Lifecycle Timeline
2DescriptionCVE.org
A flaw was found in gnome-remote-desktop as shipped in Red Hat Enterprise Linux. When the daemon is running in system mode with RDP enabled, the incoming connection handler bypasses the connection throttler, allowing an unauthenticated remote attacker to open many parallel pre-authentication connections to the RDP listener. This can accumulate accepted sockets and pending routing-token operations until timeout, exhausting resources and preventing legitimate users from establishing RDP sessions. This issue does not affect the upstream version.
AnalysisAI
Denial of service in gnome-remote-desktop as shipped in Red Hat Enterprise Linux 8, 9, and 10 lets an unauthenticated remote attacker exhaust server resources when the daemon runs in system mode with RDP enabled. Because the incoming connection handler bypasses the connection throttler, an attacker can open large numbers of parallel pre-authentication RDP connections, accumulating accepted sockets and pending routing-token operations until timeout and blocking legitimate RDP logins. There is no public exploit identified at time of analysis, and the flaw is specific to Red Hat's build - it does not affect the upstream project.
Technical ContextAI
gnome-remote-desktop is the GNOME desktop's remote-access daemon that provides RDP (and VNC) connectivity; 'system mode' runs it as a headless system service so users can RDP into a login screen rather than an already-running user session. The root cause is CWE-400 (Uncontrolled Resource Consumption): a connection throttler that is meant to rate-limit or cap concurrent incoming RDP sessions is bypassed in the accept path, so each new TCP connection to the RDP listener is fully accepted and drives an expensive pre-authentication routing-token operation before any credentials are checked. The CPE data scopes this to Red Hat's downstream packages for RHEL 8, 9, and 10 (cpe:2.3:a:red_hat:red_hat_enterprise_linux_8/9/10), and the description explicitly notes the upstream gnome-remote-desktop code is not affected, indicating a Red Hat-specific patch or backport introduced or exposed the throttler bypass.
RemediationAI
No vendor-released patch version is identified in the available data; monitor and apply the Red Hat errata referenced at https://access.redhat.com/security/cve/CVE-2026-18358 and Bugzilla 2462876 (https://bugzilla.redhat.com/show_bug.cgi?id=2462876), then update the gnome-remote-desktop package via 'dnf update gnome-remote-desktop' once the fixed NVR is published for your RHEL 8/9/10 release. Until patched, the most effective compensating control is to restrict network reachability of the RDP listener (default TCP 3389) - firewall it so only trusted management hosts or a VPN can connect, which prevents arbitrary attackers from opening pre-auth connection floods but does not stop an authorized internal host from abusing it. If remote RDP login is not required, disable gnome-remote-desktop system mode entirely (stop/mask the system service), eliminating the exposure at the cost of removing headless RDP access. Rate-limiting new connections to the listener at the network layer (e.g. iptables/nftables connlimit on port 3389) is a partial mitigation that caps parallel connections but may also throttle legitimate bursts of users.
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Same weakness CWE-400 – Uncontrolled Resource Consumption
View allSame technique Denial Of Service
View allVendor StatusVendor
SUSE
Severity: Important| Product | Status |
|---|---|
| SUSE Linux Enterprise Desktop 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Module for Package Hub 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Server 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Server 16.0 | Not-Affected |
| SUSE Linux Enterprise Server 16.1 | Not-Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Server for SAP applications 16.0 | Not-Affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | Not-Affected |
| SUSE Linux Enterprise Workstation Extension 15 SP7 | Not-Affected |
| openSUSE Leap 16.0 | Not-Affected |
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