CVE-2026-32853

UNKNOWN 0.0

LibVNCServer UltraZip Encoding Heap Out-of-bounds Read

CVSS Score

0.0

EPSS Score

0.0%

EPSS Percentile

12th

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.

CWE	CWE-125
Vendor	libvnc
Product	libvncserver
Published	Mar 24, 2026
Last Updated	Mar 25, 2026

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Affected Versions

LibVNC / LibVNCServer

0 ≤ 0.9.15

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/LibVNC/libvncserver/security/advisories/GHSA-87q7-v983-qwcj github.com: https://github.com/LibVNC/libvncserver/commit/009008e2f4d5a54dd71f422070df3af7b3dbc931 vulncheck.com: https://www.vulncheck.com/advisories/libvncserver-ultrazip-encoding-heap-out-of-bounds-read

Credits

Kazuma Matsumoto, a security researcher at GMO Cybersecurity by IERAE, Inc.