CVE-2026-50264 [High] | Out-of-bounds Write in X Server

An out-of-bounds write flaw was found in the X.Org X server and Xwayland in DRIGetBuffers/DRIGetBuffersWithFormat. A client that requests multiple DRI2BufferBackLeft attachments and one DRI2BufferFrontLeft can trigger an out-of-bounds heap write. This may be used to crash the server, or for privilege escalation if the X server runs as root.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-23	0.18%	0.14%	-0.04%
2	2026-06-15	0.01%	0.18%	+0.17%
3	2026-06-05	—	0.01%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-23

0.18%

0.14%

-0.04%

2026-06-15

0.01%

0.18%

+0.17%

2026-06-05

—

0.01%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.8	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	5.9	[email protected]
7.8	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	5.9	0b0ca135-0b70-47e7-9f44-1890c2a1c46c

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.8

3.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

5.9

[email protected]

7.8

3.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

5.9

0b0ca135-0b70-47e7-9f44-1890c2a1c46c

OS Trackers for CVE-2026-50264

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2026-50264 not yet assigned priority: Debian including 2 source packages (xorg-server, xwayland), 9 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5, open 4.	https://security-tracker.debian.org/tracker/CVE-2026-50264
`suse`	high	CVE-2026-50264 severity important: SUSE including 2 source package names (xwayland, xwayland-devel), 6 product×package rows across 4 product lines (SUSE Linux Enterprise Server 16.0, SUSE Linux Enterprise Server for SAP applications 16.0, SUSE Linux Enterprise Workstation Extension 15 SP7, openSUSE Leap 16.0): Known Not Affected 6.	https://www.suse.com/security/cve/CVE-2026-50264/
`ubuntu`	medium	CVE-2026-50264 medium priority: Ubuntu including 7 source packages (xorg, xorg-hwe-16.04, …), 46 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): needs-triage 17, DNE 16, not-affected 12, released 1.	https://ubuntu.com/security/CVE-2026-50264

Affected software / configurations for CVE-2026-50264

Vendor	Product	Version	Raw CPE
x.org	x_server	< 21.1.23	cpe:2.3:a:x.org:x_server::::::::
x.org	xwayland	< 24.1.12	cpe:2.3:a:x.org:xwayland::::::::
redhat	enterprise_linux	7.0	cpe:2.3:o:redhat:enterprise_linux:7.0:::::::*
redhat	enterprise_linux	8.0	cpe:2.3:o:redhat:enterprise_linux:8.0:::::::*
redhat	enterprise_linux	9.0	cpe:2.3:o:redhat:enterprise_linux:9.0:::::::*
redhat	enterprise_linux	10.0	cpe:2.3:o:redhat:enterprise_linux:10.0:::::::*

References for CVE-2026-50264

URL	Tags
https://access.redhat.com/errata/RHSA-2026:26562
https://access.redhat.com/errata/RHSA-2026:26566
https://access.redhat.com/errata/RHSA-2026:26590
https://access.redhat.com/errata/RHSA-2026:26610
https://access.redhat.com/errata/RHSA-2026:26709
https://access.redhat.com/errata/RHSA-2026:28923
https://access.redhat.com/errata/RHSA-2026:29844
https://access.redhat.com/security/cve/CVE-2026-50264	Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2485389	Issue Tracking Third Party Advisory
https://gitlab.freedesktop.org/xorg/xserver/-/commit/339c279514326134b0878fc23ce6e9520440ce7f	Patch
https://lists.x.org/archives/xorg-announce/2026-June/003702.html	Mailing List Vendor Advisory
https://redhat.atlassian.net/browse/PSIRTSUPT-16950	Permissions Required
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-50264.json

URL

CVE-2026-50264 | Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: out-of-bounds heap write in dri2 drigetbuffers/drigetbufferswithformat

Exploit prediction scoring system (EPSS) score for CVE-2026-50264

Common vulnerability scoring system (CVSS) metrics for CVE-2026-50264

Weakness enumeration for CVE-2026-50264

GitHub Security Advisory for CVE-2026-50264

OS Trackers for CVE-2026-50264

Affected software / configurations for CVE-2026-50264

References for CVE-2026-50264