Information disclosure or crash via unterminated wide string
Published Jul 1, 2026 · Updated Jul 1, 2026
Out-of-bounds read in UltraVNC 1.8.2.2 and earlier allows attackers to disclose adjacent memory or crash a process. The vncWc2Mb() helper in rfb/dh.cpp passes a caller-supplied WCHAR pointer to wcslen() before checking whether the buffer is NUL-terminated, so the scan continues beyond its allocation. Reachability requires an abnormal Win32 caller contract; the over-read exposes nearby memory or crashes the process if it crosses an unmapped page.
Summary
What happened
Out-of-bounds read in UltraVNC 1.8.2.2 and earlier allows attackers to disclose adjacent memory or crash a process. The vncWc2Mb() helper in rfb/dh.cpp passes a caller-supplied WCHAR pointer to wcslen() before checking whether the buffer is NUL-terminated, so the scan continues beyond its allocation. Reachability requires an abnormal Win32 caller contract; the over-read exposes nearby memory or crashes the process if it crosses an unmapped page.
The record
- CVE
- CVE-2026-44041
- Published
- Jul 1, 2026
- Updated
- Jul 1, 2026
- Vendor
- UltraVNC Team
- Product
- UltraVNC
- Classifications
- CWE-125
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 1, 2026CVE publishedPublication date reported by the CVE source.
- Jul 1, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=0 <=1.8.2.2
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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