CVSS 4.0
6.9 mediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:NCVE-2026-32853
Medium (6.9) in libvncserver project libvncserver. EPSS 0.4% chance of exploitation in the next 30 days.
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.
Severity
CVSS 3.1
8.1 highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H- EPSS
- 0.4% chance of exploitation in the next 30 days; higher than 38% of CVEs (scores of 2026-10-31)
- CWE
- CWE-125
- Published
- Modified
- Record from
- the NVD, synced
Affected
- libvncserver_project:libvncserver
References
- https://github.com/LibVNC/libvncserver/commit/009008e2f4d5a54dd71f422070df3af7b3dbc931
- 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://github.com/LibVNC/libvncserver/security/advisories/GHSA-87q7-v983-qwcj