UBUNTU-CVE-2026-32853

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    UBUNTU-CVE-2026-32853

    Published: 24 Mar 2026Last Modified: 23 Jun 2026
    Upstream:
    CVE-2026-32853
    Aliases:
    USN-8463-1

    Summary:

    Details: LibVNCServer versions 0.9.15 and prior (fixed in commit 009008e) contain a heap out-of-bounds read vulnerability in the UltraZip encoding handler that allows a malicious VNC server to cause information disclosure or application crash. Attackers can exploit improper bounds checking in the HandleUltraZipBPP() function by manipulating subrectangle header counts to read beyond the allocated heap buffer.

    References: https://ubuntu.com/security/CVE-2026-32853, https://www.cve.org/CVERecord?id=CVE-2026-32853, https://github.com/LibVNC/libvncserver/security/advisories/GHSA-87q7-v983-qwcj, https://www.vulncheck.com/advisories/libvncserver-ultrazip-encoding-heap-out-of-bounds-read, https://ubuntu.com/security/notices/USN-8463-1

    Affected packages

    Package

    Name: tightvnc

    Purl: pkg:deb/ubuntu/tightvnc?arch=source&distro=esm-infra-legacy%2Ftrusty

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -None

    Affected versions

    1.3.9-6.4
    1.3.9-6.4ubuntu1
    1.3.9-6.5+deb8u1build0.14.04.1~esm1

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    UBUNTU-CVE-2026-32853 | CVE-DB