Описание
A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256] indexed by key type index. The helper function CheckKeyTypes() writes to this buffer at a client-controlled offset, allowing a stack buffer overflow. This may be used to crash the server, or for privilege escalation if the X server runs as root.
Отчет
Red Hat rates this issue as Important impact. In xorg-x11-server and xorg-x11-server-Xwayland, _XkbSetMapChecks() uses a fixed 256-element stack buffer mapWidths[] indexed by a client-controlled key type index. CheckKeyTypes() writes beyond the buffer boundary, causing a stack buffer overflow. Any local user who can connect to the X server display can attempt exploitation. Upstream fixed this in xorg-server 21.1.23 and xwayland 24.1.12.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 6 | xorg-x11-server | Out of support scope | ||
| Red Hat Enterprise Linux 10 | xorg-x11-server-Xwayland | Fixed | RHSA-2026:26566 | 22.06.2026 |
| Red Hat Enterprise Linux 10.0 Extended Update Support | xorg-x11-server-Xwayland | Fixed | RHSA-2026:36798 | 08.07.2026 |
| Red Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSION | tigervnc | Fixed | RHSA-2026:49519 | 03.08.2026 |
| Red Hat Enterprise Linux 7 Extended Lifecycle Support | xorg-x11-server | Fixed | RHSA-2026:36083 | 07.07.2026 |
| Red Hat Enterprise Linux 7 Extended Lifecycle Support | tigervnc | Fixed | RHSA-2026:46473 | 27.07.2026 |
| Red Hat Enterprise Linux 8 | xorg-x11-server-Xwayland | Fixed | RHSA-2026:26562 | 17.06.2026 |
| Red Hat Enterprise Linux 8 | xorg-x11-server | Fixed | RHSA-2026:26709 | 17.06.2026 |
| Red Hat Enterprise Linux 8 | tigervnc | Fixed | RHSA-2026:28923 | 24.06.2026 |
| Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | xorg-x11-server | Fixed | RHSA-2026:36792 | 08.07.2026 |
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Дополнительная информация
Статус:
EPSS
7.8 High
CVSS3
Связанные уязвимости
A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256] indexed by key type index. The helper function CheckKeyTypes() writes to this buffer at a client-controlled offset, allowing a stack buffer overflow. This may be used to crash the server, or for privilege escalation if the X server runs as root.
A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256] indexed by key type index. The helper function CheckKeyTypes() writes to this buffer at a client-controlled offset, allowing a stack buffer overflow. This may be used to crash the server, or for privilege escalation if the X server runs as root.
Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: stack buffer overflow in xkb setmap request via mapwidths indexing
A stack-based buffer overflow flaw was found in the X.Org X server and ...
A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256] indexed by key type index. The helper function CheckKeyTypes() writes to this buffer at a client-controlled offset, allowing a stack buffer overflow. This may be used to crash the server, or for privilege escalation if the X server runs as root.
EPSS
7.8 High
CVSS3