CVE Feed

    Dashboard / CVE / CVE-2026-32853

    CVE-2026-32853

    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.

    Published:Mar 24, 2026
    Last Modified:Jul 14, 2026
    EPS:Mar 24, 2026
    EPSS Score:0.00437
    CVSS Score:8.1

    Affected Products

    Vendor
    Libvnc Project
    Product
    Libvncserver
    Vendor
    Libvncserver
    Product
    Libvncserver
    Vendor
    Libvncserver Project
    Product
    Libvncserver

    Exploits

    https://www.vulncheck.com/advisories/libvncserver-ultrazip-encoding-heap-out-of-bounds-read

    Common Weakness Enumeration

    CWE-125 Out-of-bounds Read

    Common Attack Pattern Enumeration and Classification (CAPEC)

    CAPEC-540 Overread Buffers

    Related CVEs

    CVE-2026-32854 (CVSS 6.3) — LibVNCServer versions 0.9.15 and prior (fixed in commit dc78dee) contain null pointer dereference vulnerabilit…
    CVE-2018-21247 (CVSS 7.5) — An issue was discovered in LibVNCServer before 0.9.13. There is an information leak (of uninitialized memory c…
    CVE-2020-14404 (CVSS 5.4) — An issue was discovered in LibVNCServer before 0.9.13. libvncserver/rre.c allows out-of-bounds access via enco…
    CVE-2020-14398 (CVSS 7.5) — An issue was discovered in LibVNCServer before 0.9.13. An improperly closed TCP connection causes an infinite …
    CVE-2020-14402 (CVSS 5.4) — An issue was discovered in LibVNCServer before 0.9.13. libvncserver/corre.c allows out-of-bounds access via en…
    CVE-2020-14397 (CVSS 7.5) — An issue was discovered in LibVNCServer before 0.9.13. libvncserver/rfbregion.c has a NULL pointer dereference…
    CVE-2020-14396 (CVSS 7.5) — An issue was discovered in LibVNCServer before 0.9.13. libvncclient/tls_openssl.c has a NULL pointer dereferen…
    CVE-2020-14403 (CVSS 5.4) — An issue was discovered in LibVNCServer before 0.9.13. libvncserver/hextile.c allows out-of-bounds access via …
    CVE-2019-20840 (CVSS 7.5) — An issue was discovered in LibVNCServer before 0.9.13. libvncserver/ws_decode.c can lead to a crash because of…
    CVE-2019-20839 (CVSS 7.5) — libvncclient/sockets.c in LibVNCServer before 0.9.13 has a buffer overflow via a long socket filename.…

    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