A flaw was discovered in the X.Org X server’s X Keyboard (Xkb) extension when handling client resource cleanup. The software frees certain data structures without properly detaching related resources, leading to a use-after-free condition. This can cause memory corruption or a crash when affected clients disconnect.
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Xorg-server | Ubuntu | jammy | * |
| Xorg-server | Ubuntu | noble | * |
| Xorg-server | Ubuntu | plucky | * |
| Xorg-server | Ubuntu | questing | * |
| Xorg-server | Ubuntu | upstream | * |
| Xwayland | Ubuntu | jammy | * |
| Xwayland | Ubuntu | noble | * |
| Xwayland | Ubuntu | plucky | * |
| Xwayland | Ubuntu | questing | * |
| Xwayland | Ubuntu | upstream | * |