CVE-2026-44041
MEDIUM
4.3
CVSS 3.1
Description
UltraVNC through 1.8.2.2 contains an out-of-bounds read in the wide-string to multibyte conversion helper. In rfb/dh.cpp:204, the vncWc2Mb() function passes a caller-supplied WCHAR pointer to wcslen() before any bounds check. If the caller provides a wide-character buffer that is not properly NUL-terminated, wcslen() reads past the end of the buffer until it encounters a NUL wchar, resulting in an out-of-bounds read. Under typical Win32 API usage this requires an abnormal caller contract. Impact is limited to a potential information disclosure from adjacent memory regions or a process crash (denial of service) if the over-read crosses a page boundary.
Metadata
Severity & Metrics
4.3
MEDIUM CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Affected products (1)
| Vendor | Product | Platform | Versions |
|---|---|---|---|
| uvnc | UltraVNC | — | 0 ≤ 1.8.2.2 |
Weakness (CWE)
| CWE | Source | Description |
|---|---|---|
| CWE-125 | cna | Out-of-bounds Read |
CVSS scores (1)
| Score | Severity | Version | Source | Vector |
|---|---|---|---|---|
| 4.3 | MEDIUM | 3.1 | cna | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L |
References (2)
- UltraVNC project page https://uvnc.com/
- UltraVNC source repository https://github.com/ultravnc/UltraVNC