CVE-2026-109833 Red Hat CVE debrief

Who should care

System administrators and security teams responsible for Red Hat Enterprise Linux 8, 9, and 10 deployments with gnome-remote-desktop and exposed VNC TLS listeners should assess their exposure and prioritize patching.

Why it matters

CVE-2026-109833 is a medium-severity vulnerability in gnome-remote-desktop that can lead to denial of service via a heap buffer overflow. Defenders should prioritize patching and verifying VNC TLS listener configurations, especially in environments with exposed listeners.

• Denial of service via remote exploitation
• Potential disruption to critical systems and services
• Need for verification of patch deployment and VNC TLS listener configurations
• Possible impact on incident response and system recovery efforts

Technical summary

The gnome-remote-desktop component has a heap buffer overflow vulnerability in its VNC TLS read path. This occurs due to incorrect handling of the internal peek buffer, allowing a remote attacker to cause an out-of-bounds write and resulting in a denial of service. The vulnerability is caused by partial consumption of the internal peek buffer incorrectly moving remaining peeked bytes into the caller-supplied buffer instead of compacting the peek buffer. Defenders should prioritize verifying and patching vulnerable gnome-remote-desktop installations, especially in environments with exposed VNC TLS listeners.

Defensive priority

Defenders should prioritize verifying and patching vulnerable gnome-remote-desktop installations, especially in environments with exposed VNC TLS listeners.

Recommended defensive actions

• Verify and apply patches for gnome-remote-desktop on Red Hat Enterprise Linux 8, 9, and 10
• Restrict access to VNC TLS listeners to trusted sources
• Monitor for suspicious VNC activity
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE Program and NVD provide official records of this vulnerability. Red Hat also provides a security advisory for this issue. The vulnerability is confirmed to affect Red Hat Enterprise Linux 8, 9, and 10. There is no evidence of public exploitation, but defenders should prioritize patching and verifying VNC TLS listener configurations. The source item and CVE Program record provide additional details on the vulnerability.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.