Xorg: xwayland: heap overflow in xkbwritekeysyms()
Noroxi assessment
Priority: Monitor (action score 31/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.43% (FIRST EPSS).
- Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: gitlab.freedesktop.org/xorg/xserver/ xserver 21.1.16, 24.1.6; azl3 xorg-x11-server-Xwayland 24.1.1-3 on Azure Linux 3.0 24.1.6-1; azl3 xorg-x11-server-Xwayland 24.1.6-1 on Azure Linux 3.0 24.1.6-1.
Low priority for now. Upgrade to gitlab.freedesktop.org/xorg/xserver/ xserver 21.1.16, 24.1.6; azl3 xorg-x11-server-Xwayland 24.1.1-3 on Azure Linux 3.0 24.1.6-1; azl3 xorg-x11-server-Xwayland 24.1.6-1 on Azure Linux 3.0 24.1.6-1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
A heap overflow flaw was found in X.Org and Xwayland. The computation of the length in XkbSizeKeySyms() differs from what is written in XkbWriteKeySyms(), which may lead to a heap-based buffer overflow.
- BDU:2025-06970
- ALSA-2025:2500
- ALSA-2025:2502
- ALSA-2025:7163
- ALSA-2025:7165
- DLA-4072-1
- DSA-5872-1
- openSUSE-SU-2025:14841-1
- openSUSE-SU-2025:14842-1
- RHSA-2025:2500
- RHSA-2025:2502
- RHSA-2025:2861
- RHSA-2025:2862
- RHSA-2025:2865
- RHSA-2025:2866
- RHSA-2025:2873
- RHSA-2025:2874
- RHSA-2025:2875
- RHSA-2025:2879
- RHSA-2025:2880
- Published
- Feb 25, 2025
- Updated
- Jun 29, 2026
- EPSS
- 0.4% · 36th percentile
- CWE
- CWE-787
Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 7.8
- CNA · redhat
- 7.8
- agree
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| x.org | x server | cpe:2.3:a:x.org:x_server |
| x.org | xwayland | cpe:2.3:a:x.org:xwayland |
| tigervnc | tigervnc | cpe:2.3:a:tigervnc:tigervnc |
| redhat | enterprise linux | cpe:2.3:o:redhat:enterprise_linux |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- redhat enterprise linux7.0
- redhat enterprise linux8.0
- redhat enterprise linux9.0
- tigervnc tigervncall versions
- x.org x serverbefore 21.1.16
- x.org xwaylandbefore 24.1.6
Versions reported by the vendor
Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.
gitlab.freedesktop.org/xorg/xserver/ xserver
- before 21.1.16affected · semver
- 22.0.0 and later · before 24.1.6affected · semver
Red Hat Red Hat Enterprise Linux 10
- 0:24.1.5-3.el10_0 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 6
- all versionsunknown
Red Hat Red Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSION
- 0:1.1.0-25.el6_10 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support
- 0:1.8.0-36.el7_9 and laternot affected · rpm
- 0:1.20.4-30.el7_9 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8
- 0:1.13.1-15.el8_10 and laternot affected · rpm
- all versionsunknown
- all versionsunknown
Red Hat Red Hat Enterprise Linux 8.2 Advanced Update Support
- 0:1.9.0-15.el8_2.13 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
- 0:1.11.0-8.el8_4.12 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.4 Telecommunications Update Service
- 0:1.11.0-8.el8_4.12 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions
- 0:1.11.0-8.el8_4.12 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
- 0:1.12.0-6.el8_6.13 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.6 Telecommunications Update Service
- 0:1.12.0-6.el8_6.13 and laternot affected · rpm
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:8 | tigervnc | before 1.13.1-15.el8_10 | 1.13.1-15.el8_10 |
| AlmaLinux:8 | tigervnc-icons | before 1.13.1-15.el8_10 | 1.13.1-15.el8_10 |
| AlmaLinux:8 | tigervnc-license | before 1.13.1-15.el8_10 | 1.13.1-15.el8_10 |
| AlmaLinux:8 | tigervnc-selinux | before 1.13.1-15.el8_10 | 1.13.1-15.el8_10 |
| AlmaLinux:8 | tigervnc-server | before 1.13.1-15.el8_10 | 1.13.1-15.el8_10 |
| AlmaLinux:8 | tigervnc-server-minimal | before 1.13.1-15.el8_10 | 1.13.1-15.el8_10 |
| AlmaLinux:8 | tigervnc-server-module | before 1.13.1-15.el8_10 | 1.13.1-15.el8_10 |
| AlmaLinux:9 | tigervnc | before 1.14.1-1.el9_5.1 | 1.14.1-1.el9_5.1 |
| AlmaLinux:9 | tigervnc-icons | before 1.14.1-1.el9_5.1 | 1.14.1-1.el9_5.1 |
| AlmaLinux:9 | tigervnc-license | before 1.14.1-1.el9_5.1 | 1.14.1-1.el9_5.1 |
| AlmaLinux:9 | tigervnc-selinux | before 1.14.1-1.el9_5.1 | 1.14.1-1.el9_5.1 |
| AlmaLinux:9 | tigervnc-server | before 1.14.1-1.el9_5.1 | 1.14.1-1.el9_5.1 |
| AlmaLinux:9 | tigervnc-server-minimal | before 1.14.1-1.el9_5.1 | 1.14.1-1.el9_5.1 |
| AlmaLinux:9 | tigervnc-server-module | before 1.14.1-1.el9_5.1 | 1.14.1-1.el9_5.1 |
| AlmaLinux:9 | xorg-x11-server-common | before 1.20.11-28.el9_6 | 1.20.11-28.el9_6 |
| AlmaLinux:9 | xorg-x11-server-devel | before 1.20.11-28.el9_6 | 1.20.11-28.el9_6 |
| AlmaLinux:9 | xorg-x11-server-source | before 1.20.11-28.el9_6 | 1.20.11-28.el9_6 |
| AlmaLinux:9 | xorg-x11-server-Xdmx | before 1.20.11-28.el9_6 | 1.20.11-28.el9_6 |
| AlmaLinux:9 | xorg-x11-server-Xephyr | before 1.20.11-28.el9_6 | 1.20.11-28.el9_6 |
| AlmaLinux:9 | xorg-x11-server-Xnest | before 1.20.11-28.el9_6 | 1.20.11-28.el9_6 |
| AlmaLinux:9 | xorg-x11-server-Xorg | before 1.20.11-28.el9_6 | 1.20.11-28.el9_6 |
| AlmaLinux:9 | xorg-x11-server-Xvfb | before 1.20.11-28.el9_6 | 1.20.11-28.el9_6 |
| AlmaLinux:9 | xorg-x11-server-Xwayland | before 23.2.7-3.el9_6 | 23.2.7-3.el9_6 |
| AlmaLinux:9 | xorg-x11-server-Xwayland-devel | before 23.2.7-3.el9_6 | 23.2.7-3.el9_6 |
+96
Same product
x.org: all recordsOther highest-scoring records for the same primary product.
- CVE-2023-6816Xorg-x11-server: heap buffer overflow in devicefocusevent and procxiquerypointer40Plan
- CVE-2007-6427The XInput extension in X.Org Xserver before 1.4.1 allows context-dependent attackers to execute arbitrary code via requests related to byte38Monitor
- CVE-2026-56000xorg-x11-server / xwayland GLX contextTags Use-After-Free in CommonMakeCurrent()36Monitor
- CVE-2026-34002Xorg: xwayland: x.org x server: information disclosure or denial of service via out-of-bounds read in xkb modifier map handling36Monitor
- CVE-2026-34000Xwayland: xorg: x.org x server: information disclosure and denial of service via out-of-bounds read in xkb geometry processing.36Monitor
- CVE-2022-46344A vulnerability was found in X.Org.36Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| gitlab.freedesktop.org/xorg/xserver/ xserver | 21.1.16 | Vendor (CNA) |
| gitlab.freedesktop.org/xorg/xserver/ xserver | 24.1.6 | Vendor (CNA) |
| azl3 xorg-x11-server-Xwayland 24.1.1-3 on Azure Linux 3.0 | 24.1.6-1 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 xorg-x11-server-Xwayland 24.1.6-1 on Azure Linux 3.0 | 24.1.6-1 · CBL-Mariner Releases | Microsoft (MSRC) |
| cbl2 xorg-x11-server 1.20.10-15 on CBL Mariner 2.0 | 1.20.10-15 · CBL-Mariner Releases | Microsoft (MSRC) |
| cbl2 xorg-x11-server 1.20.10-15 on CBL-Mariner 2.0 | 1.20.10-15 · CBL-Mariner Releases | Microsoft (MSRC) |
| almalinux:tigervnc | 1.14.1-1.el9_5.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:tigervnc-icons | 1.14.1-1.el9_5.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:tigervnc-license | 1.14.1-1.el9_5.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:tigervnc-selinux | 1.14.1-1.el9_5.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:tigervnc-server | 1.14.1-1.el9_5.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:tigervnc-server-minimal | 1.14.1-1.el9_5.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:tigervnc-server-module | 1.14.1-1.el9_5.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:xorg-x11-server-Xdmx | 1.20.11-28.el9_6 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:xorg-x11-server-Xephyr | 1.20.11-28.el9_6 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:xorg-x11-server-Xnest | 1.20.11-28.el9_6 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:xorg-x11-server-Xorg | 1.20.11-28.el9_6 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:xorg-x11-server-Xvfb | 1.20.11-28.el9_6 · AlmaLinux:9 | Package registry (OSV) |
| debian:xorg-server | 2:21.1.7-3+deb12u9 · Debian:12 | Package registry (OSV) |
| debian:xwayland | 2:24.1.6-1 · Debian:13 | Package registry (OSV) |
| opensuse:xorg-x11-server | 21.1.11-150600.5.6.1 · openSUSE:Leap 15.6 | Package registry (OSV) |
| opensuse:xwayland | 24.1.1-150600.5.9.1 · openSUSE:Leap 15.6 | Package registry (OSV) |
| red hat:tigervnc | 0:1.14.1-1.el9_5.1 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:tigervnc-debuginfo | 0:1.14.1-1.el9_5.1 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:tigervnc-debugsource | 0:1.14.1-1.el9_5.1 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:tigervnc-icons | 0:1.14.1-1.el9_5.1 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:tigervnc-license | 0:1.14.1-1.el9_5.1 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:tigervnc-selinux | 0:1.14.1-1.el9_5.1 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:tigervnc-server | 0:1.14.1-1.el9_5.1 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:tigervnc-server-debuginfo | 0:1.14.1-1.el9_5.1 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
+9
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2023-6816404 days apartXorg-x11-server: heap buffer overflow in devicefocusevent and procxiquerypointer40Plan
- CVE-2025-265980 days apartXorg: xwayland: out-of-bounds write in createpointerbarrierclient()31Monitor
- CVE-2024-0229382 days apartXorg-x11-server: reattaching to different master device may lead to out-of-bounds memory access31Monitor
- CVE-2024-0409404 days apartXorg-x11-server: selinux context corruption31Monitor
- CVE-2026-50264465 days apartXorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: out-of-bounds heap write in dri2 drigetbuffers/drigetbufferswithformat31Monitor
- CVE-2023-5367489 days apartXorg-x11-server: out-of-bounds write in xichangedeviceproperty/rrchangeoutputproperty31Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-787 · Out-of-bounds WriteCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (17 more)Show less
- access.redhat.com/errata/RHSA-2025:2502
- access.redhat.com/errata/RHSA-2025:2861
- access.redhat.com/errata/RHSA-2025:2862
- access.redhat.com/errata/RHSA-2025:2865
- access.redhat.com/errata/RHSA-2025:2866
- access.redhat.com/errata/RHSA-2025:2873
- access.redhat.com/errata/RHSA-2025:2874
- access.redhat.com/errata/RHSA-2025:2875
- access.redhat.com/errata/RHSA-2025:2879
- access.redhat.com/errata/RHSA-2025:2880
- access.redhat.com/errata/RHSA-2025:3976
- access.redhat.com/errata/RHSA-2025:7163
- access.redhat.com/errata/RHSA-2025:7165
- access.redhat.com/errata/RHSA-2025:7458
- access.redhat.com/security/cve/CVE-2025-26596
- bugzilla.redhat.com/show_bug.cgi?id=2345256
- lists.debian.org/debian-lts-announce/2025/02/msg00036.html
Vendor advisories and official records. Exploit/PoC links are deliberately left out.