PatchSiren cyber security CVE debrief
CVE-2026-52720 Red Hat CVE debrief
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.
- Vendor
- Red Hat
- Product
- Red Hat Enterprise Linux 10
- CVSS
- HIGH 8.8
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-06-15
- Original CVE updated
- 2026-06-15
- Advisory published
- 2026-06-15
- Advisory updated
- 2026-06-15
Who should care
Users of GStreamer's librfb (RFB/VNC client) should be aware of this vulnerability and take steps to mitigate it.
Technical summary
The vulnerability is caused by the rectangle bounds check incorrectly validating area rather than individual dimensions. This allows a malicious VNC server to send a rectangle that extends beyond the framebuffer, resulting in an out-of-bounds heap write.
Defensive priority
HIGH
Recommended defensive actions
- Apply patches or updates from the vendor as soon as they are available.
- Use secure VNC connections and validate the authenticity of VNC servers.
- Limit access to VNC servers to trusted users and networks.
Evidence notes
The CVE-2026-52720 vulnerability has been reported by Redhat. For more information, see resourceLinkAnnotations: [ref-4, ref-5, ref-6].
Official resources
CVE-2026-52720 was published on 2026-06-15T20:16:32.580Z and modified on 2026-06-15T21:09:52.020Z.