---
id: CVE-2026-52720
title: >-
  A heap buffer overflow vulnerability was found in GStreamer's librfb (RFB/VNC
  client)
summary: >-
  A heap buffer overflow vulnerability was found in GStreamer's librfb (RFB/VNC
  client). The rectangle bounds check incorrectly validates area rather than
  individual dimensions, allowing a malicious VNC server to send a rectangle
  that exte…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'
cwe:
  - CWE-122
  - CWE-122
published: '2026-06-15'
updated: '2026-07-28'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-52720'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2026:36749'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:36834'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:37130'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:47069'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:47070'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:47071'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:47075'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:47076'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:47176'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/security/cve/CVE-2026-52720'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2486731'
    label: secalert@redhat.com
  - url: 'https://gitlab.freedesktop.org/gstreamer/gstreamer/-/work_items/5105'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:36749'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:36834'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:37130'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/security/cve/CVE-2026-52720'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2486731'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52720.json
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
tags:
  - nvd
epss: 0.0118
epssPercentile: 0.66368
ingestedAt: '2026-07-28T21:39:18.064Z'
---

## Overview

A heap buffer overflow vulnerability was found in GStreamer's librfb (RFB/VNC client). The rectangle bounds check incorrectly validates area rather than individual dimensions, allowing a malicious VNC server to send a rectangle that extends beyond the framebuffer. A remote attacker could set up a malicious VNC server and trick a user into connecting, resulting in an out-of-bounds heap write that could lead to code execution or a crash.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.