CVE catalog
CVE-2026-44041
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()
- Severity
- Medium · CVSS 4.3
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.41% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Cpe | ultravnc | Not reported | Not reported | unknown |
| Cpe | ultravnc | Not reported | Not reported | unknown |
Fixed-version evidence
OpenFactory catalog packages
No matching packages in this catalog.
Observed:
References
- [https://github.com/ultravnc/UltraVNC]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-44041]
- [https://uvnc.com/]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-2162.json]
- [https://www.securin.io/zero-days/cve-2026-44041-vncwc2mb-wcslen-before-bounds-check-ultravnc]
[CERT-Bund public advisories] · [FIRST EPSS] · [National Vulnerability Database (NVD)]