Tigervnc

A use-after-free flaw was found in X.Org and Xwayland

CVE-2025-26594 7.8 - High - February 25, 2025

A use-after-free flaw was found in X.Org and Xwayland. The root cursor is referenced in the X server as a global variable. If a client frees the root cursor, the internal reference points to freed memory and causes a use-after-free.

Dangling pointer

A buffer overflow flaw was found in X.Org and Xwayland

CVE-2025-26595 7.8 - High - February 25, 2025

A buffer overflow flaw was found in X.Org and Xwayland. The code in XkbVModMaskText() allocates a fixed-sized buffer on the stack and copies the names of the virtual modifiers to that buffer. The code fails to check the bounds of the buffer and would copy the data regardless of the size.

Memory Corruption

A heap overflow flaw was found in X.Org and Xwayland

CVE-2025-26596 7.8 - High - February 25, 2025

A heap overflow flaw was found in X.Org and Xwayland. The computation of the length in XkbSizeKeySyms() differs from what is written in XkbWriteKeySyms(), which may lead to a heap-based buffer overflow.

Memory Corruption

A buffer overflow flaw was found in X.Org and Xwayland

CVE-2025-26597 7.8 - High - February 25, 2025

A buffer overflow flaw was found in X.Org and Xwayland. If XkbChangeTypesOfKey() is called with a 0 group, it will resize the key symbols table to 0 but leave the key actions unchanged. If the same function is later called with a non-zero value of groups, this will cause a buffer overflow because the key actions are of the wrong size.

Buffer Overflow

An out-of-bounds write flaw was found in X.Org and Xwayland

CVE-2025-26598 7.8 - High - February 25, 2025

An out-of-bounds write flaw was found in X.Org and Xwayland. The function GetBarrierDevice() searches for the pointer device based on its device ID and returns the matching value, or supposedly NULL, if no match was found. However, the code will return the last element of the list if no matching device ID is found, which can lead to out-of-bounds memory access.

Memory Corruption

An access to an uninitialized pointer flaw was found in X.Org and Xwayland

CVE-2025-26599 7.8 - High - February 25, 2025

An access to an uninitialized pointer flaw was found in X.Org and Xwayland. The function compCheckRedirect() may fail if it cannot allocate the backing pixmap. In that case, compRedirectWindow() will return a BadAlloc error without validating the window tree marked just before, which leaves the validated data partly initialized and the use of an uninitialized pointer later.

Access of Uninitialized Pointer

A use-after-free flaw was found in X.Org and Xwayland

CVE-2025-26600 7.8 - High - February 25, 2025

A use-after-free flaw was found in X.Org and Xwayland. When a device is removed while still frozen, the events queued for that device remain while the device is freed. Replaying the events will cause a use-after-free.

Dangling pointer

A use-after-free flaw was found in X.Org and Xwayland

CVE-2025-26601 7.8 - High - February 25, 2025

A use-after-free flaw was found in X.Org and Xwayland. When changing an alarm, the values of the change mask are evaluated one after the other, changing the trigger values as requested, and eventually, SyncInitTrigger() is called. If one of the changes triggers an error, the function will return early, not adding the new sync object, possibly causing a use-after-free when the alarm eventually triggers.

Dangling pointer

A flaw was found in the X.Org server

CVE-2024-0408 5.5 - Medium - January 18, 2024

A flaw was found in the X.Org server. The GLX PBuffer code does not call the XACE hook when creating the buffer, leaving it unlabeled. When the client issues another request to access that resource (as with a GetGeometry) or when it creates another resource that needs to access that buffer, such as a GC, the XSELINUX code will try to use an object that was never labeled and crash because the SID is NULL.

A flaw was found in the X.Org server

CVE-2024-0409 7.8 - High - January 18, 2024

A flaw was found in the X.Org server. The cursor code in both Xephyr and Xwayland uses the wrong type of private at creation. It uses the cursor bits type with the cursor as private, and when initiating the cursor, that overwrites the XSELINUX context.

Memory Corruption

In rfb/CSecurityTLS.cxx and rfb/CSecurityTLS.java in TigerVNC before 1.11.0, viewers mishandle TLS certificate exceptions

CVE-2020-26117 8.1 - High - September 27, 2020

In rfb/CSecurityTLS.cxx and rfb/CSecurityTLS.java in TigerVNC before 1.11.0, viewers mishandle TLS certificate exceptions. They store the certificates as authorities, meaning that the owner of a certificate could impersonate any server after a client had added an exception.

Improper Certificate Validation

TigerVNC version prior to 1.10.1 is vulnerable to stack buffer overflow, which could be triggered from CMsgReader::readSetCursor

CVE-2019-15695 7.2 - High - December 26, 2019

TigerVNC version prior to 1.10.1 is vulnerable to stack buffer overflow, which could be triggered from CMsgReader::readSetCursor. This vulnerability occurs due to insufficient sanitization of PixelFormat. Since remote attacker can choose offset from start of the buffer to start writing his values, exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity.

Memory Corruption

TigerVNC version prior to 1.10.1 is vulnerable to stack use-after-return

CVE-2019-15691 7.2 - High - December 26, 2019

TigerVNC version prior to 1.10.1 is vulnerable to stack use-after-return, which occurs due to incorrect usage of stack memory in ZRLEDecoder. If decoding routine would throw an exception, ZRLEDecoder may try to access stack variable, which has been already freed during the process of stack unwinding. Exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity.

Operation on a Resource after Expiration or Release

TigerVNC version prior to 1.10.1 is vulnerable to heap buffer overflow, which could be triggered from DecodeManager::decodeRect

CVE-2019-15694 7.2 - High - December 26, 2019

TigerVNC version prior to 1.10.1 is vulnerable to heap buffer overflow, which could be triggered from DecodeManager::decodeRect. Vulnerability occurs due to the signdness error in processing MemOutStream. Exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity.

Improper Input Validation

TigerVNC version prior to 1.10.1 is vulnerable to heap buffer overflow, which occurs in TightDecoder::FilterGradient

CVE-2019-15693 7.2 - High - December 26, 2019

TigerVNC version prior to 1.10.1 is vulnerable to heap buffer overflow, which occurs in TightDecoder::FilterGradient. Exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity.

Memory Corruption

TigerVNC version prior to 1.10.1 is vulnerable to heap buffer overflow

CVE-2019-15692 7.2 - High - December 26, 2019

TigerVNC version prior to 1.10.1 is vulnerable to heap buffer overflow. Vulnerability could be triggered from CopyRectDecoder due to incorrect value checks. Exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity.

Memory Corruption

The CSecurityTLS::processMsg function in common/rfb/CSecurityTLS.cxx in the vncviewer component in TigerVNC 1.1beta1 does not properly verify the server's X.509 certificate, which

CVE-2011-1775 - May 26, 2011

The CSecurityTLS::processMsg function in common/rfb/CSecurityTLS.cxx in the vncviewer component in TigerVNC 1.1beta1 does not properly verify the server's X.509 certificate, which allows man-in-the-middle attackers to spoof a TLS VNC server via an arbitrary certificate.

Improper Input Validation