Heap buffer overflow in X.Org Server RandR ChangeProviderProperty
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 6 fixed, 4 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-122 and the CVSS impact.
Summary
X.Org X Server before 21.1.25 and XWayland before 24.1.14 are affected. A heap buffer overflow in RandR ChangeProviderProperty requests (CWE-122) lets authenticated X clients crash the X server or execute code within its context.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
A buffer overflow in RandR ChangeProviderProperty requests in X.Org X Server before 2.1.25 and XWayland before 24.4.14 could be used by authenticated X clients to crash or execute code within the X server context.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Upgrade X.Org X Server (xorg-x11-server) to 21.1.25 and XWayland to 24.1.14. Red Hat fixes this in RHSA-2026:89747, RHSA-2026:86907, RHSA-2026:85193, RHSA-2026:85191 and RHSA-2026:82015. Red Hat Enterprise Linux 6, 7, 8 and 9 are affected without a fix, and Red Hat has no plan available for Red Hat Enterprise Linux 7, 8 and 9.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA xorg-x11-server (x.org) Fixed in 21.1.25
- Fix · CNA xwayland (x.org) Fixed in 24.1.14
Red Hat 5 advisories
- RHSA-2026:89747 Released 2026-10-26 · Red Hat rating Importantxorg-x11-server security update
- Red Hat Enterprise Linux AppStream (v. 8) xorg-x11-server-1.20.11-28.el8_10.5, xorg-x11-server-Xdmx-1.20.11-28.el8_10.5, xorg-x11-server-Xephyr-1.20.11-28.el8_10.5 +4
- Red Hat Enterprise Linux CRB (v. 8) xorg-x11-server-devel-1.20.11-28.el8_10.5, xorg-x11-server-source-1.20.11-28.el8_10.5
- RHSA-2026:86907 Released 2026-10-21 · Red Hat rating Importantxorg-x11-server-Xwayland security update
- Red Hat Enterprise Linux AppStream (v. 8) xorg-x11-server-Xwayland-21.1.3-20.el8_10.4
- RHSA-2026:85193 Released 2026-10-19 · Red Hat rating Importantxorg-x11-server-Xwayland security update
- Red Hat Enterprise Linux AppStream (v. 9) xorg-x11-server-Xwayland-24.1.9-4.el9_8.4
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) xorg-x11-server-Xwayland-24.1.9-4.el9_8.4, xorg-x11-server-Xwayland-devel-24.1.9-4.el9_8.4
Show 2 more Red Hat advisories
- RHSA-2026:85191 Released 2026-10-19 · Red Hat rating Importantxorg-x11-server-Xwayland security update
- Red Hat Enterprise Linux AppStream (v. 10) xorg-x11-server-Xwayland-24.1.9-4.el10_2.4
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) xorg-x11-server-Xwayland-devel-24.1.9-4.el10_2.4
- RHSA-2026:82015 Released 2026-10-13 · Red Hat rating Importantxorg-x11-server security update
- Red Hat Enterprise Linux AppStream (v. 9) xorg-x11-server-1.20.11-34.el9_8.4, xorg-x11-server-Xdmx-1.20.11-34.el9_8.4, xorg-x11-server-Xephyr-1.20.11-34.el9_8.4 +4
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) xorg-x11-server-devel-1.20.11-34.el9_8.4, xorg-x11-server-source-1.20.11-34.el9_8.4
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
x.org xorg-x11-server 21.1.25
10 records Highest priority Priority LOW 10 LOW
Other records, highest priority first
- TI-2026-82016 Heap buffer overflow in X.Org X Server XInput2 request handlingPriority LOW 35
- TI-2026-82013 X.Org Server Glamor CopyArea Heap Buffer OverflowPriority LOW 35
- TI-2026-82007 Heap buffer overflow in X.Org X server XKB keycode range handlingPriority LOW 35
- Release ·
x.org xwayland 24.1.14
10 records Highest priority Priority LOW 10 LOW
Other records, highest priority first
- TI-2026-81987 Heap buffer overflow in X.Org Server GLX RenderLarge requestPriority LOW 38
- TI-2026-82016 Heap buffer overflow in X.Org X Server XInput2 request handlingPriority LOW 35
- TI-2026-82013 X.Org Server Glamor CopyArea Heap Buffer OverflowPriority LOW 35
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | — |
| Red Hat Enterprise Linux 7 | Affected | No fix yet |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:85191 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2026:86907, RHSA-2026:89747 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:82015, RHSA-2026:85193 |
| Red Hat Enterprise Linux CRB (v. 8) | Fixed | RHSA-2026:89747 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) | Fixed | RHSA-2026:85191 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2026:82015, RHSA-2026:85193 |
Timeline
- 2026-10-28 Threatist record created from CVE-2026-93521
- 2026-10-28 Alias added: GHSA-8q64-4f7g-q2rf
- 2026-10-30 Priority changed: MEDIUM → LOW
References
More x.org vulnerabilities
- TI-2022-25238 In X.Org X server 20.11 through 21.1.16, when a client application uses easystroke for… CVSS 3.1HIGH 7.7
- TI-1999-00519 An X server's access control is disabled (e.g. CVSS 2.0HIGH 10.0
- TI-2021-11657 LookupCol.c in X.Org X through X11R7.7 and libX11 before 1.7.1 might allow remote… CVSS 3.1CRITICAL 9.8
- TI-2018-10465 An issue was discovered in libX11 through 1.6.5. CVSS 3.0CRITICAL 9.8
- TI-2004-00826 Multiple vulnerabilities in libXpm for 6.8.1 and earlier, as used in XFree86 and other… CVSS 2.0HIGH 10.0
- TI-2016-08240 Multiple integer overflows in libXpm before 3.5.12, when a program requests parsing XPM… CVSS 3.0CRITICAL 9.8
Sources
- CVE-2026-93521 · CVE Program
- CVE-2026-93521 · NVD
- FIRST EPSS
- GHSA-8q64-4f7g-q2rf · GitHub Advisory Database · CC BY 4.0
- CVE-2026-93521 · Red Hat security data · CC BY 4.0
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