{"id":"CVE-2026-44041","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-44041","generatedAt":"2026-10-28T02:12:02.730Z","title":"UltraVNC through 1.8.2.2 contains an out-of-bounds read in the wide-string to multibyte conversion helper.","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.","published":"2026-07-01T05:16:21.000Z","lastModified":"2026-10-25T17:10:00.000Z","status":"Modified","sourceIdentifier":"33c584b5-0579-4c06-b2a0-8d8329fcab9c","cvss":{"version":"3.1","score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L"},"cwe":["CWE-125"],"affected":["uvnc/ultravnc"],"epss":{"score":0.00413,"percentile":0.35332,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.41%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/ultravnc/UltraVNC","tags":["Product"],"source":"33c584b5-0579-4c06-b2a0-8d8329fcab9c"},{"url":"https://uvnc.com/","tags":["Product","Release Notes"],"source":"33c584b5-0579-4c06-b2a0-8d8329fcab9c"},{"url":"https://www.securin.io/zero-days/cve-2026-44041-vncwc2mb-wcslen-before-bounds-check-ultravnc","source":"33c584b5-0579-4c06-b2a0-8d8329fcab9c"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-44041","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}