SB2026102645 - Red Hat Enterprise Linux 8 update for xorg-x11-server-Xwayland
Published: October 26, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 8 vulnerabilities.
1) Use-after-free (CVE-ID: CVE-2026-93516)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to compromise vulnerable system.
The vulnerability exists due to a use-after-free error within the handling of DeviceInt objects. A local user can gain access to sensitive information on the system.
2) Heap-based buffer overflow (CVE-ID: CVE-2026-93521)
CWE-ID: CWE-122 - Heap-based Buffer Overflow
CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error within the RRChangeProviderProperty function. A local user can pass specially crafted data to the application, trigger a heap-based buffer overflow and execute arbitrary code with elevated privileges.
3) Double free (CVE-ID: CVE-2026-88812)
CWE-ID: CWE-415 - Double Free
CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to escalate privileges on the target system.
The vulnerability exists due to a boundary error within the handling of SetGeometry requests. A local user can pass specially crafted data to the application, trigger double free error and gain elevated privileges on the system.
4) Heap-based buffer overflow (CVE-ID: CVE-2026-93523)
CWE-ID: CWE-122 - Heap-based Buffer Overflow
CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error within the handling of modifier fields. A local user can pass specially crafted data to the application, trigger a heap-based buffer overflow and execute arbitrary code with elevated privileges.
5) Heap-based buffer overflow (CVE-ID: CVE-2026-93517)
CWE-ID: CWE-122 - Heap-based Buffer Overflow
CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error within the glXDisp_RenderLarge function. A local user can pass specially crafted data to the application, trigger a heap-based buffer overflow and execute arbitrary code with elevated privileges.
6) Numeric Truncation Error (CVE-ID: CVE-2026-93518)
CWE-ID: CWE-197 - Numeric Truncation Error
CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to numeric truncation error within the handling of XkbSetMap requests, which leads to security restrictions bypass and privilege escalation.
7) Heap-based buffer overflow (CVE-ID: CVE-2026-93519)
CWE-ID: CWE-122 - Heap-based Buffer Overflow
CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error within the input_constrain_cursor function. A local user can pass specially crafted data to the application, trigger a heap-based buffer overflow and execute arbitrary code with elevated privileges.
8) Heap-based buffer overflow (CVE-ID: CVE-2026-93520)
CWE-ID: CWE-122 - Heap-based Buffer Overflow
CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error within the XkbChangeKeycodeRange function. A local user can pass specially crafted data to the application, trigger a heap-based buffer overflow and execute arbitrary code with elevated privileges.
Remediation
Install update from vendor's website.