Details for this vulnerability have not been published by NIST at this point. Descriptions from software vendor advisories for this issue are provided below.
The X.org project reports:
All theses issuses can lead to local privileges elevation on
systems where the X server is running privileged.
The handler for the XkbSetNames request does not validate the
request length before accessing its contents.
An integer underflow exists in the handler for the
An integer underflow exist in the handler for the XkbSelectEvents
An integer underflow exist in the handler for the CreateRegister
request of the X record extension.