CVE-2023-3255 MEDIUM

CVE-2023-3255: Qemu: vnc: infinite loop in inflate_buffer() leads to denial of service

Vendor Red Hat
Product Red Hat Enterprise Linux 6
Weakness CWE-835
Published September 13, 2023
Last update November 8, 2025

CVSS base score

6.5/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

What the vulnerability does

01Description

A flaw was found in the QEMU built-in VNC server while processing ClientCutText messages. A wrong exit condition may lead to an infinite loop when inflating an attacker controlled zlib buffer in the `inflate_buffer` function. This could allow a remote authenticated client who is able to send a clipboard to the VNC server to trigger a denial of service.

Key dates

02Disclosure timeline

September 13, 2023 CVE published
November 8, 2025 Record updated