synced 11 MIN AGO
01 Record

CVE-2026-50256

Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: stack buffer overflow in font alias resolution due to libxfont2 name length mismatch

HighPUBLISHEDCNA: redhat
CNA base score7.8 CVSS v3.xCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
View raw JSON

02 Description

Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: stack buffer overflow in font alias resolution due to libxfont2 name length mismatch

03 Exploitation and scoring

Exploitation
Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
SSVC decision
  • ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
  • AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
  • Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.15% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 4.8% of scored records. A rank, not a probability.
NVD base score
7.8 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD analysis status
Modified. NVD last modified this record on 2026-08-05.
Red Hat severity
Important. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2026-06-05 10:31Z4 MO AGO
Last updated
2026-09-28 11:45Z1 MO AGO
Reserved
2026-06-04
Assigning CNA
redhat
Record state
PUBLISHED
Severity
High (CVSS 7.8)
CNA CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weaknesses
  • CWE-121Stack-based Buffer OverflowVariant
Data version
5.2
Document digest
e42287dd753afea2176d0b86efc8081bb34cf96c9cd891475ba6ae8e597f8a15

05 Affected products

VendorProductVersionsPlatforms
Red HatRed Hat Enterprise Linux 10Not specified—
Red HatRed Hat Enterprise Linux 10.0 Extended Update SupportNot specified—
Red HatRed Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSIONNot specified—
Red HatRed Hat Enterprise Linux 7 Extended Lifecycle SupportNot specified—
Red HatRed Hat Enterprise Linux 8Not specified—
Red HatRed Hat Enterprise Linux 8.4 Advanced Mission Critical Update SupportNot specified—
Red HatRed Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-OnNot specified—
Red HatRed Hat Enterprise Linux 8.6 Advanced Mission Critical Update SupportNot specified—
Red HatRed Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-OnNot specified—
Red HatRed Hat Enterprise Linux 8.8 Telecommunications Update ServiceNot specified—
Red HatRed Hat Enterprise Linux 8.8 Update Services for SAP SolutionsNot specified—
Red HatRed Hat Enterprise Linux 9Not specified—
Red HatRed Hat Enterprise Linux 9.2 Update Services for SAP SolutionsNot specified—
Red HatRed Hat Enterprise Linux 9.4 Update Services for SAP SolutionsNot specified—
Red HatRed Hat Enterprise Linux 9.6 Extended Update SupportNot specified—
Red HatRed Hat Enterprise Linux 6Not specified—

06 References

07 Fixed in

AlmaLinux 8

  • tigervnc
    Fixed in 1.15.0-10.el8_10
  • tigervnc-icons
    Fixed in 1.15.0-10.el8_10
  • tigervnc-license
    Fixed in 1.15.0-10.el8_10
  • tigervnc-selinux
    Fixed in 1.15.0-10.el8_10
  • tigervnc-server
    Fixed in 1.15.0-10.el8_10
  • tigervnc-server-minimal
    Fixed in 1.15.0-10.el8_10
  • tigervnc-server-module
    Fixed in 1.15.0-10.el8_10
  • xorg-x11-server-Xdmx
    Fixed in 1.20.11-28.el8_10.2
  • xorg-x11-server-Xephyr
    Fixed in 1.20.11-28.el8_10.2
  • xorg-x11-server-Xnest
    Fixed in 1.20.11-28.el8_10.2
  • xorg-x11-server-Xorg
    Fixed in 1.20.11-28.el8_10.2
  • xorg-x11-server-Xvfb
    Fixed in 1.20.11-28.el8_10.2
  • xorg-x11-server-Xwayland
    Fixed in 21.1.3-20.el8_10.2
  • xorg-x11-server-common
    Fixed in 1.20.11-28.el8_10.2
  • xorg-x11-server-devel
    Fixed in 1.20.11-28.el8_10.2
  • xorg-x11-server-source
    Fixed in 1.20.11-28.el8_10.2

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

AlmaLinux 9

  • tigervnc
    Fixed in 1.15.0-7.el9_8.2
  • tigervnc-icons
    Fixed in 1.15.0-7.el9_8.2
  • tigervnc-license
    Fixed in 1.15.0-7.el9_8.2
  • tigervnc-selinux
    Fixed in 1.15.0-7.el9_8.2
  • tigervnc-server
    Fixed in 1.15.0-7.el9_8.2
  • tigervnc-server-minimal
    Fixed in 1.15.0-7.el9_8.2
  • tigervnc-server-module
    Fixed in 1.15.0-7.el9_8.2
  • xorg-x11-server-Xdmx
    Fixed in 1.20.11-34.el9_8.2
  • xorg-x11-server-Xephyr
    Fixed in 1.20.11-34.el9_8.2
  • xorg-x11-server-Xnest
    Fixed in 1.20.11-34.el9_8.2
  • xorg-x11-server-Xorg
    Fixed in 1.20.11-34.el9_8.2
  • xorg-x11-server-Xvfb
    Fixed in 1.20.11-34.el9_8.2
  • xorg-x11-server-Xwayland
    Fixed in 24.1.9-4.el9_8.2
  • xorg-x11-server-Xwayland-devel
    Fixed in 24.1.9-4.el9_8.2
  • xorg-x11-server-common
    Fixed in 1.20.11-34.el9_8.2
  • xorg-x11-server-devel
    Fixed in 1.20.11-34.el9_8.2
  • xorg-x11-server-source
    Fixed in 1.20.11-34.el9_8.2

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

AlmaLinux 10

  • xorg-x11-server-Xwayland
    Fixed in 24.1.9-4.el10_2.2
  • xorg-x11-server-Xwayland-devel
    Fixed in 24.1.9-4.el10_2.2

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 8

  • tigervnc
    Fixed in 1.15.0-10.el8_10
  • tigervnc-icons
    Fixed in 1.15.0-10.el8_10
  • tigervnc-license
    Fixed in 1.15.0-10.el8_10
  • tigervnc-selinux
    Fixed in 1.15.0-10.el8_10
  • tigervnc-server
    Fixed in 1.15.0-10.el8_10
  • tigervnc-server-minimal
    Fixed in 1.15.0-10.el8_10
  • tigervnc-server-module
    Fixed in 1.15.0-10.el8_10
  • xorg-x11-server-Xdmx
    Fixed in 1.20.11-28.el8_10.2
  • xorg-x11-server-Xephyr
    Fixed in 1.20.11-28.el8_10.2
  • xorg-x11-server-Xnest
    Fixed in 1.20.11-28.el8_10.2
  • xorg-x11-server-Xorg
    Fixed in 1.20.11-28.el8_10.2
  • xorg-x11-server-Xvfb
    Fixed in 1.20.11-28.el8_10.2
  • xorg-x11-server-Xwayland
    Fixed in 21.1.3-20.el8_10.2
  • xorg-x11-server-common
    Fixed in 1.20.11-28.el8_10.2
  • xorg-x11-server-devel
    Fixed in 1.20.11-28.el8_10.2
  • xorg-x11-server-source
    Fixed in 1.20.11-28.el8_10.2

Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 9

  • tigervnc
    Fixed in 1.15.0-7.el9_8.2
  • tigervnc-icons
    Fixed in 1.15.0-7.el9_8.2
  • tigervnc-license
    Fixed in 1.15.0-7.el9_8.2
  • tigervnc-selinux
    Fixed in 1.15.0-7.el9_8.2
  • tigervnc-server
    Fixed in 1.15.0-7.el9_8.2
  • tigervnc-server-minimal
    Fixed in 1.15.0-7.el9_8.2
  • tigervnc-server-module
    Fixed in 1.15.0-7.el9_8.2
  • xorg-x11-server-Xdmx
    Fixed in 1.20.11-34.el9_8.2
  • xorg-x11-server-Xephyr
    Fixed in 1.20.11-34.el9_8.2
  • xorg-x11-server-Xnest
    Fixed in 1.20.11-34.el9_8.2
  • xorg-x11-server-Xorg
    Fixed in 1.20.11-34.el9_8.2
  • xorg-x11-server-Xvfb
    Fixed in 1.20.11-34.el9_8.2
  • xorg-x11-server-Xwayland
    Fixed in 24.1.9-4.el9_8.2
  • xorg-x11-server-Xwayland-devel
    Fixed in 24.1.9-4.el9_8.2
  • xorg-x11-server-common
    Fixed in 1.20.11-34.el9_8.2
  • xorg-x11-server-devel
    Fixed in 1.20.11-34.el9_8.2
  • xorg-x11-server-source
    Fixed in 1.20.11-34.el9_8.2

Derived from AlmaLinux 9. Partial coverage: only packages taken from AlmaLinux 9 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 10

  • xorg-x11-server-Xwayland
    Fixed in 24.1.9-4.el10_2.2
  • xorg-x11-server-Xwayland-devel
    Fixed in 24.1.9-4.el10_2.2

Derived from AlmaLinux 10. Partial coverage: only packages taken from AlmaLinux 10 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

Debian 12

  • xorg-server
    Fixed in 2:21.1.7-3+deb12u13
  • xwayland
    No fix yet

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

  • xorg-server
    Fixed in 2:21.1.16-1.3+deb13u3
  • xwayland
    No fix yet

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

  • xorg-server
    Fixed in 2:21.1.23-1
  • xwayland
    Fixed in 2:24.1.12-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 22.04 LTS

  • xorg-server
    No fix yet
  • xwayland
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 24.04 LTS

  • xorg-server
    No fix yet
  • xwayland
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 25.10

  • xorg-server
    No fix yet
  • xwayland
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 26.04 LTS

  • xorg-server
    No fix yet
  • xwayland
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 26.10

  • xorg-server
    No fix yet
  • xwayland
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 14.04 LTS

  • xorg-server
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 16.04 LTS

  • xorg-server
    No fix yet
  • xorg-server-hwe-16.04
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 18.04 LTS

  • xorg-server
    No fix yet
  • xorg-server-hwe-18.04
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 20.04 LTS

  • xorg-server
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.