A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. A mismatch between the X server and the libXfont2 library's maximum font name length can cause a stack buffer overflow during font alias resolution. The server allocates a 256 byte stack buffer but libXfont2's alias target name length is 1024 bytes. A font alias name between 257 and 1023 bytes causes the X server to copy that name into the undersized stack buffer without further checks. This may be used to crash the server, or for privilege escalation if the X server runs as root.
References
Configurations
Configuration 1 (hide)
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History
27 Jul 2026, 13:18
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| References | () https://access.redhat.com/errata/RHSA-2026:46377 - | |
| References | () https://access.redhat.com/errata/RHSA-2026:46382 - | |
| References | () https://access.redhat.com/errata/RHSA-2026:46385 - | |
| References | () https://access.redhat.com/errata/RHSA-2026:46392 - | |
| References | () https://access.redhat.com/errata/RHSA-2026:46456 - | |
| References | () https://access.redhat.com/errata/RHSA-2026:46460 - | |
| References | () https://access.redhat.com/errata/RHSA-2026:46473 - |
27 Jul 2026, 10:16
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27 Jul 2026, 08:16
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27 Jul 2026, 07:16
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27 Jul 2026, 04:16
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13 Jul 2026, 13:16
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| References | () https://access.redhat.com/errata/RHSA-2026:38502 - | |
| References | () https://access.redhat.com/errata/RHSA-2026:38810 - |
13 Jul 2026, 12:16
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13 Jul 2026, 06:16
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09 Jul 2026, 13:17
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| References | () https://access.redhat.com/errata/RHSA-2026:36768 - | |
| References | () https://access.redhat.com/errata/RHSA-2026:36791 - | |
| References | () https://access.redhat.com/errata/RHSA-2026:36792 - | |
| References | () https://access.redhat.com/errata/RHSA-2026:36798 - |
09 Jul 2026, 04:17
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08 Jul 2026, 17:17
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08 Jul 2026, 13:16
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| References | () https://access.redhat.com/errata/RHSA-2026:36632 - | |
| References | () https://access.redhat.com/errata/RHSA-2026:36633 - | |
| References | () https://access.redhat.com/errata/RHSA-2026:36634 - |
08 Jul 2026, 10:16
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07 Jul 2026, 12:16
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| References | () https://access.redhat.com/errata/RHSA-2026:36086 - |
07 Jul 2026, 08:16
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30 Jun 2026, 03:20
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| References | () https://access.redhat.com/errata/RHSA-2026:26562 - | |
| References | () https://access.redhat.com/errata/RHSA-2026:26566 - | |
| References | () https://access.redhat.com/errata/RHSA-2026:26590 - | |
| References | () https://access.redhat.com/errata/RHSA-2026:26610 - | |
| References | () https://access.redhat.com/errata/RHSA-2026:26709 - | |
| References | () https://access.redhat.com/errata/RHSA-2026:28923 - | |
| References | () https://access.redhat.com/errata/RHSA-2026:29844 - | |
| References | () https://access.redhat.com/security/cve/CVE-2026-50256 - Vendor Advisory | |
| References | () https://bugzilla.redhat.com/show_bug.cgi?id=2485380 - Issue Tracking, Vendor Advisory |
25 Jun 2026, 14:16
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24 Jun 2026, 11:16
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22 Jun 2026, 08:17
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18 Jun 2026, 02:16
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08 Jun 2026, 16:45
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| CPE | cpe:2.3:a:x.org:xwayland:*:*:*:*:*:*:*:* cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:* cpe:2.3:a:x.org:x_server:*:*:*:*:*:*:*:* cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* |
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| References | () https://access.redhat.com/security/cve/CVE-2026-50256 - Vendor Advisory | |
| References | () https://bugzilla.redhat.com/show_bug.cgi?id=2485380 - Issue Tracking, Vendor Advisory | |
| References | () https://gitlab.freedesktop.org/xorg/xserver/-/commit/bb5158f962dc935e58ef8b4b5fcb31be201a6e07 - Patch | |
| References | () https://lists.x.org/archives/xorg-announce/2026-June/003702.html - Mailing List, Third Party Advisory | |
| References | () https://redhat.atlassian.net/browse/PSIRTSUPT-16950 - Permissions Required | |
| First Time |
Redhat enterprise Linux
Redhat X.org X.org xwayland X.org x Server |
05 Jun 2026, 12:16
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| New CVE |
Information
Published : 2026-06-05 12:16
Updated : 2026-07-27 13:18
NVD link : CVE-2026-50256
Mitre link : CVE-2026-50256
CVE.ORG link : CVE-2026-50256
JSON object : View
Products Affected
x.org
- x_server
- xwayland
redhat
- enterprise_linux
CWE
CWE-121
Stack-based Buffer Overflow
