CVE-2026-50256

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Source
https://cve.org/CVERecord?id=CVE-2026-50256
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-50256.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-50256
Downstream
Related
Published
2026-06-05T10:31:22.122Z
Modified
2026-06-23T04:02:34.695971024Z
Severity
  • 7.8 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: stack buffer overflow in font alias resolution due to libxfont2 name length mismatch
Details

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.

Database specific 
{
    "cna_assigner": "redhat",
    "cwe_ids": [
        "CWE-121"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50256.json"
}
References

Affected packages

Git / gitlab.freedesktop.org/xorg/xserver

Affected ranges

Type
GIT
Repo
https://gitlab.freedesktop.org/xorg/xserver
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
8570e9fcec845f68f0c90caa51fd7a24764ea220
Fixed
af4b3d7250366e1a3822919e41fcf66da4966af2
Fixed
bb5158f962dc935e58ef8b4b5fcb31be201a6e07
Database specific 
{
    "cpe": [
        "cpe:2.3:a:x.org:x_server:*:*:*:*:*:*:*:*",
        "cpe:2.3:a:x.org:xwayland:*:*:*:*:*:*:*:*",
        "cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*"
    ],
    "source": [
        "CPE_RANGE",
        "CPE_STRING",
        "REFERENCES"
    ],
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "21.1.23"
        },
        {
            "fixed": "24.1.12"
        },
        {
            "last_affected": "7.0"
        }
    ]
}

Affected versions

Other
DRI-XFree86-4_3_99_12-merge
DRI-trunk-20040613
DRI-trunk-20040721
DRM-1_0_5
DRM-20040613
DRM-20040721
DRM-20050615
DRM-20051017
DRM-2_0_0
Domain-base
Domain-sync1
Domain-sync2
Domain-sync3
Domain-sync4
MODULAR_COPY
PRE_xf86-4_3_0_1
XACE-SELINUX-MERGE
XORG-6_7_99_1
XORG-6_7_99_2
XORG-6_7_99_901
XORG-6_7_99_902
XORG-6_7_99_903
XORG-6_7_99_904
XORG-6_8_0
XORG-6_8_99_1
XORG-6_8_99_10
XORG-6_8_99_11
XORG-6_8_99_12
XORG-6_8_99_13
XORG-6_8_99_14
XORG-6_8_99_15
XORG-6_8_99_16
XORG-6_8_99_2
XORG-6_8_99_3
XORG-6_8_99_4
XORG-6_8_99_5
XORG-6_8_99_6
XORG-6_8_99_7
XORG-6_8_99_8
XORG-6_8_99_9
XORG-6_8_99_900
XORG-6_8_99_901
XORG-6_8_99_902
XORG-6_8_99_903
XORG-6_99_99_900
XORG-6_99_99_901
XORG-6_99_99_902
XORG-6_99_99_903
XORG-6_99_99_904
XORG-7_0
XORG-7_0_99_901
XORG-MAIN
add-Xi
ah-20021030
ah-20021030-postdri
before-mesa-4_0-import
dhd-20010328
dhd-20010817
dhd-20020916
dri-0-1-branchpoint
dri-20020129-merge
dri-20020222-merge
kdrive-initial-import
keithp
lg3d-base
pre-R651-import
pre-xgldrop-merge
sco_port_update-base
xf-3_9_16Z
xf-3_9_16Za
xf-3_9_16d
xf-3_9_16e
xf-3_9_16f
xf-3_9_17
xf-3_9_17Z
xf-3_9_17a
xf-3_9_17b
xf-3_9_17c
xf-3_9_17d
xf-3_9_17e
xf-3_9_17f
xf-3_9_18
xf-3_9_18Z
xf-3_9_18Za
xf-3_9_18a
xf-3_9_18b
xf-4_0
xf-4_0-bindist
xf-4_0Z
xf-4_0_1
xf-4_0_1-bindist
xf-4_0_1Z
xf-4_0_1Za
xf-4_0_1Zb
xf-4_0_1Zc
xf-4_0_1a
xf-4_0_1b
xf-4_0_1c
xf-4_0_1d
xf-4_0_1e
xf-4_0_1f
xf-4_0_1g
xf-4_0_1h
xf-4_0_2
xf-4_0_2-bindist
xf-4_0_99_1
xf-4_0_99_2
xf-4_0_99_3
xf-4_0_99_900
xf-4_0a
xf-4_0b
xf-4_0c
xf-4_0d
xf-4_0e
xf-4_0f
xf-4_0g
xf-4_1_99_1
xf-4_1_99_2
xf-4_1_99_3
xf-4_1_99_4
xf-4_1_99_5
xf-4_1_99_6
xf-4_1_99_7
xf-4_2-bp
xf-4_2_0
xf-4_2_0-bindist
xf-4_2_0-bindist-1
xf-4_2_0_1
xf-4_2_1
xf-4_2_1_1
xf-4_2_99_1
xf-4_2_99_2
xf-4_2_99_3
xf-4_2_99_4
xf-4_2_99_901
xf-4_2_99_902
xf-4_3_0
xf-4_3_0_1
xf-4_3_99_1
xf-4_3_99_2
xf-4_3_99_3
xf-4_3_99_4
xf-4_3_99_5
xf-4_3_99_6
xf86-012804-2330
xf86-4_3_0_1
xf86-4_3_99_16
xf86-4_3_99_901
xf86-4_3_99_902
xf86-4_3_99_903
xf86-4_3_99_903_special
xf86-4_4_0
xf86-4_4_99_1
xfixes_2_branchpoint
xorg-server-0_99_1
xorg-server-1_0_99_1
xorg-server-1_0_99_2
xorg-server-1_0_99_901
xorg-server-1_1_99_1
xorg-server-1_1_99_2
xorg-server-1.*
xorg-server-1.1.99.3
xorg-server-1.10.0
xorg-server-1.10.99.901
xorg-server-1.10.99.902
xorg-server-1.11.0
xorg-server-1.11.99.1
xorg-server-1.11.99.901
xorg-server-1.11.99.902
xorg-server-1.11.99.903
xorg-server-1.12.0
xorg-server-1.12.99.901
xorg-server-1.12.99.902
xorg-server-1.12.99.903
xorg-server-1.12.99.904
xorg-server-1.12.99.905
xorg-server-1.13.0
xorg-server-1.13.99.901
xorg-server-1.13.99.902
xorg-server-1.14.0
xorg-server-1.14.99.1
xorg-server-1.14.99.2
xorg-server-1.14.99.3
xorg-server-1.14.99.901
xorg-server-1.14.99.902
xorg-server-1.14.99.903
xorg-server-1.14.99.904
xorg-server-1.14.99.905
xorg-server-1.15.0
xorg-server-1.15.99.901
xorg-server-1.15.99.902
xorg-server-1.15.99.903
xorg-server-1.15.99.904
xorg-server-1.16.0
xorg-server-1.16.99.901
xorg-server-1.16.99.902
xorg-server-1.17.0
xorg-server-1.17.99.901
xorg-server-1.17.99.902
xorg-server-1.18.0
xorg-server-1.18.99.2
xorg-server-1.18.99.901
xorg-server-1.18.99.902
xorg-server-1.19.0
xorg-server-1.19.99.901
xorg-server-1.19.99.902
xorg-server-1.19.99.903
xorg-server-1.19.99.904
xorg-server-1.19.99.905
xorg-server-1.20.0
xorg-server-1.5.99.1
xorg-server-1.6.99.900
xorg-server-1.6.99.901
xorg-server-1.7.99.1
xorg-server-1.7.99.2
xorg-server-1.7.99.901
xorg-server-1.7.99.902
xorg-server-1.8.0
xorg-server-1.8.99.901
xorg-server-1.8.99.902
xorg-server-1.8.99.903
xorg-server-1.8.99.904
xorg-server-1.8.99.905
xorg-server-1.8.99.906
xorg-server-1.9.0
xorg-server-1.9.99.901
xorg-server-1.9.99.902
xorg-server-1.9.99.903
xorg-server-21.*
xorg-server-21.0.99.1
xorg-server-21.0.99.901
xorg-server-21.0.99.902
xorg-server-21.1.0
xorg-server-21.1.1
xorg-server-21.1.10
xorg-server-21.1.11
xorg-server-21.1.12
xorg-server-21.1.13
xorg-server-21.1.14
xorg-server-21.1.15
xorg-server-21.1.16
xorg-server-21.1.17
xorg-server-21.1.18
xorg-server-21.1.19
xorg-server-21.1.2
xorg-server-21.1.20
xorg-server-21.1.21
xorg-server-21.1.22
xorg-server-21.1.3
xorg-server-21.1.4
xorg-server-21.1.5
xorg-server-21.1.6
xorg-server-21.1.7
xorg-server-21.1.8
xorg-server-21.1.9
xwayland-24.*
xwayland-24.0.99.901
xwayland-24.0.99.902
xwayland-24.1.0
xwayland-24.1.1
xwayland-24.1.10
xwayland-24.1.11
xwayland-24.1.2
xwayland-24.1.3
xwayland-24.1.4
xwayland-24.1.5
xwayland-24.1.6
xwayland-24.1.7
xwayland-24.1.8
xwayland-24.1.9

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-50256.json"