393 matches found
EUVD-2026-40883
UltraVNC viewer through 1.8.2.2 contains an off-by-one stack buffer overflow in the RFB ServerInit message handler. In vncviewer/ClientConnection.cpp, when the server-supplied nameLength equals exactly 2024 the code declares a 2024-byte stack buffer dn2024 and calls ReadStringdn, 2024. ReadString...
CVE-2026-7831 UltraVNC viewer off-by-one stack overflow in ServerInit desktop name parsing
UltraVNC viewer through 1.8.2.2 contains an off-by-one stack buffer overflow in the RFB ServerInit message handler. In vncviewer/ClientConnection.cpp, when the server-supplied nameLength equals exactly 2024 the code declares a 2024-byte stack buffer dn2024 and calls ReadStringdn, 2024. ReadString...
CVE-2026-7831 UltraVNC viewer off-by-one stack overflow in ServerInit desktop name parsing
UltraVNC viewer through 1.8.2.2 contains an off-by-one stack buffer overflow in the RFB ServerInit message handler. In vncviewer/ClientConnection.cpp, when the server-supplied nameLength equals exactly 2024 the code declares a 2024-byte stack buffer dn2024 and calls ReadStringdn, 2024. ReadString...
EUVD-2026-40882
UltraVNC through 1.8.2.2 uses inadequate cryptography in the MS-Logon II authentication scheme rfbUltraVNCMsLogonIIAuth. In rfb/dh.cpp the Diffie-Hellman key exchange is performed with parameters that fit in an unsigned 64-bit integer DHMAXBITS controls the prime size. A 64-bit DH key can be brok...
CVE-2026-7830
CVE-2026-7830 affects UltraVNC up to version 1.8.2.2 and concerns the MS-Logon II authentication. The DH key exchange uses parameters within 64-bit space (DH_MAX_BITS) and the private exponent is generated using a rng() that relies on three libc rand() calls seeded from time(NULL). This yields an...
CVE-2026-7830 UltraVNC MS-Logon II uses 64-bit Diffie-Hellman and seeded libc rand() enabling credential interception
UltraVNC through 1.8.2.2 uses inadequate cryptography in the MS-Logon II authentication scheme rfbUltraVNCMsLogonIIAuth. In rfb/dh.cpp the Diffie-Hellman key exchange is performed with parameters that fit in an unsigned 64-bit integer DHMAXBITS controls the prime size. A 64-bit DH key can be brok...
CVE-2026-7829 UltraVNC repeater authenticated out-of-bounds write in rule parser via oversized token
UltraVNC repeater through 1.8.2.2 contains a post-authentication out-of-bounds write in the allow/deny rule parser. In repeater/webgui/settings.c:225-272, after strncpys copies a rule token into temp1rule1 25-byte destination or temp2/temp3 16-byte destination, the code unconditionally writes a N...
CVE-2026-7829 UltraVNC repeater authenticated out-of-bounds write in rule parser via oversized token
UltraVNC repeater through 1.8.2.2 contains a post-authentication out-of-bounds write in the allow/deny rule parser. In repeater/webgui/settings.c:225-272, after strncpys copies a rule token into temp1rule1 25-byte destination or temp2/temp3 16-byte destination, the code unconditionally writes a N...
CVE-2026-7829
UltraVNC repeater (= destination size, the NUL byte is written past the end of the stack array, corrupting adjacent data and potentially enabling code execution on the repeater host. An attacker with admin credentials (including via CVE-2026-7839 default password) can trigger this. The provided d...
EUVD-2026-40881
UltraVNC repeater through 1.8.2.2 contains a post-authentication out-of-bounds write in the allow/deny rule parser. In repeater/webgui/settings.c:225-272, after strncpys copies a rule token into temp1rule1 25-byte destination or temp2/temp3 16-byte destination, the code unconditionally writes a N...
CVE-2026-7829
UltraVNC repeater through 1.8.2.2 contains a post-authentication out-of-bounds write in the allow/deny rule parser. In repeater/webgui/settings.c:225-272, after strncpys copies a rule token into temp1rule1 25-byte destination or temp2/temp3 16-byte destination, the code unconditionally writes a N...
CVE-2026-7828
UltraVNC repeater through 1.8.2.2 contains an integer overflow in the HTTP request logging path. In repeater/webgui/settings.c:336, the winlog function allocates list nodes via mallocsizeofstruct LIST + strlenline, where line is derived from HTTP request URIs. If strlenline is sufficiently large,...
CVE-2026-7828
UltraVNC repeater up to version 1.8.2.2 contains an integer overflow in the HTTP request logging path. In repeater/webgui/settings.c:336, win_log() allocates memory with malloc(sizeof(struct LIST) + strlen(line)); if strlen(line) is large, the size overflows to a value smaller than sizeof(struct ...
EUVD-2026-40880
UltraVNC repeater through 1.8.2.2 contains an integer overflow in the HTTP request logging path. In repeater/webgui/settings.c:336, the winlog function allocates list nodes via mallocsizeofstruct LIST + strlenline, where line is derived from HTTP request URIs. If strlenline is sufficiently large,...
CVE-2026-7828 UltraVNC repeater integer overflow in win_log malloc leading to heap overflow
UltraVNC repeater through 1.8.2.2 contains an integer overflow in the HTTP request logging path. In repeater/webgui/settings.c:336, the winlog function allocates list nodes via mallocsizeofstruct LIST + strlenline, where line is derived from HTTP request URIs. If strlenline is sufficiently large,...
CVE-2026-7828 UltraVNC repeater integer overflow in win_log malloc leading to heap overflow
UltraVNC repeater through 1.8.2.2 contains an integer overflow in the HTTP request logging path. In repeater/webgui/settings.c:336, the winlog function allocates list nodes via mallocsizeofstruct LIST + strlenline, where line is derived from HTTP request URIs. If strlenline is sufficiently large,...
EUVD-2026-40879
UltraVNC through 1.8.2.2 uses a cryptographically weak pseudo-random number generator to produce VNC authentication challenge bytes. In rfb/vncauth.c:119-129, the vncRandomBytes function seeds libc rand with time0 + getpid + rand and generates a 16-byte challenge. The combined seed space is...
CVE-2026-44040 UltraVNC vncauth.c uses time-seeded libc rand() to generate VNC authentication challenge bytes
UltraVNC through 1.8.2.2 uses a cryptographically weak pseudo-random number generator to produce VNC authentication challenge bytes. In rfb/vncauth.c:119-129, the vncRandomBytes function seeds libc rand with time0 + getpid + rand and generates a 16-byte challenge. The combined seed space is...
CVE-2026-44040 UltraVNC vncauth.c uses time-seeded libc rand() to generate VNC authentication challenge bytes
UltraVNC through 1.8.2.2 uses a cryptographically weak pseudo-random number generator to produce VNC authentication challenge bytes. In rfb/vncauth.c:119-129, the vncRandomBytes function seeds libc rand with time0 + getpid + rand and generates a 16-byte challenge. The combined seed space is...
CVE-2026-44041 UltraVNC vncWc2Mb calls wcslen() before validating that the wide string is NUL-terminated
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...