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Noroxi
CVE-2023-5380· NVD / CVE Program· CNA redhat

Xorg-x11-server: use-after-free bug in destroywindow

Noroxi assessment

Priority: Monitor (action score 18/100)

  • 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: 0.71% (FIRST EPSS); higher than 52.6% of all records.
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: tigervnc (AlmaLinux:8) 1.13.1-8.el8; tigervnc-icons (AlmaLinux:8) 1.13.1-8.el8; tigervnc-license (AlmaLinux:8) 1.13.1-8.el8.

Low priority for now. Upgrade to tigervnc (AlmaLinux:8) 1.13.1-8.el8; tigervnc-icons (AlmaLinux:8) 1.13.1-8.el8; tigervnc-license (AlmaLinux:8) 1.13.1-8.el8 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

Primary sources: NVD · CVE.org · FIRST EPSS

A use-after-free flaw was found in the xorg-x11-server. An X server crash may occur in a very specific and legacy configuration (a multi-screen setup with multiple protocol screens, also known as Zaphod mode) if the pointer is warped from within a window on one screen to the root window of the other screen and if the original window is destroyed followed by another window being destroyed.

MediumCVSS 4.7 · v3.1—No exploit Fix available
Published
Oct 25, 2023
Updated
Jun 23, 2026
EPSS
0.7% · 53th percentile

Report tools

JSON

Action score

18

Monitor

Low priority for now.

CVSS
18 / 40 · 4.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.7%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
4.7
CNA · redhat
4.7
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.

Follow CVE-2023-5380

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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.

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Affected 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.

VendorProduct
x.orgx server
x.orgxwayland
redhatenterprise linux
fedoraprojectfedora
debiandebian linux

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • debian debian linux11.0
  • debian debian linux12.0
  • fedoraproject fedora37
  • fedoraproject fedora38
  • fedoraproject fedora39
  • redhat enterprise linux7.0
  • redhat enterprise linux8.0
  • redhat enterprise linux9.0
  • x.org x serverbefore 21.1.9
  • x.org xwaylandbefore 23.2.2

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.

  • Red Hat Red Hat Enterprise Linux 6

    • all versionsunknown
    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 7

    • 0:1.8.0-26.el7_9 and laternot affected · rpm
    • all versionsaffected

  • Red Hat Red Hat Enterprise Linux 8

    • 0:1.20.11-22.el8 and laternot affected · rpm
    • 0:1.13.1-8.el8 and laternot affected · rpm
    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 9

    • 0:1.20.11-24.el9 and laternot affected · rpm
    • 0:1.13.1-8.el9 and laternot affected · rpm
    • all versionsunknown

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:8tigervncbefore 1.13.1-8.el81.13.1-8.el8
AlmaLinux:8tigervnc-iconsbefore 1.13.1-8.el81.13.1-8.el8
AlmaLinux:8tigervnc-licensebefore 1.13.1-8.el81.13.1-8.el8
AlmaLinux:8tigervnc-selinuxbefore 1.13.1-8.el81.13.1-8.el8
AlmaLinux:8tigervnc-serverbefore 1.13.1-8.el81.13.1-8.el8
AlmaLinux:8tigervnc-server-minimalbefore 1.13.1-8.el81.13.1-8.el8
AlmaLinux:8tigervnc-server-modulebefore 1.13.1-8.el81.13.1-8.el8
AlmaLinux:8xorg-x11-server-commonbefore 1.20.11-22.el81.20.11-22.el8
AlmaLinux:8xorg-x11-server-develbefore 1.20.11-22.el81.20.11-22.el8
AlmaLinux:8xorg-x11-server-sourcebefore 1.20.11-22.el81.20.11-22.el8
AlmaLinux:8xorg-x11-server-Xdmxbefore 1.20.11-22.el81.20.11-22.el8
AlmaLinux:8xorg-x11-server-Xephyrbefore 1.20.11-22.el81.20.11-22.el8
AlmaLinux:8xorg-x11-server-Xnestbefore 1.20.11-22.el81.20.11-22.el8
AlmaLinux:8xorg-x11-server-Xorgbefore 1.20.11-22.el81.20.11-22.el8
AlmaLinux:8xorg-x11-server-Xvfbbefore 1.20.11-22.el81.20.11-22.el8
AlmaLinux:9tigervncbefore 1.13.1-8.el91.13.1-8.el9
AlmaLinux:9tigervnc-iconsbefore 1.13.1-8.el91.13.1-8.el9
AlmaLinux:9tigervnc-licensebefore 1.13.1-8.el91.13.1-8.el9
AlmaLinux:9tigervnc-selinuxbefore 1.13.1-8.el91.13.1-8.el9
AlmaLinux:9tigervnc-serverbefore 1.13.1-8.el91.13.1-8.el9
AlmaLinux:9tigervnc-server-minimalbefore 1.13.1-8.el91.13.1-8.el9
AlmaLinux:9tigervnc-server-modulebefore 1.13.1-8.el91.13.1-8.el9
AlmaLinux:9xorg-x11-server-commonbefore 1.20.11-24.el91.20.11-24.el9
AlmaLinux:9xorg-x11-server-develbefore 1.20.11-24.el91.20.11-24.el9

+82

Same product

x.org: all records

Other highest-scoring records for the same primary product.

  • CVE-2023-6816Xorg-x11-server: heap buffer overflow in devicefocusevent and procxiquerypointer
    40Plan
  • 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 byte
    38Monitor
  • 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 handling
    36Monitor
  • 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 / packageFixed versionSource
almalinux:tigervnc1.13.1-8.el9 · AlmaLinux:9Package registry (OSV)
almalinux:tigervnc-icons1.13.1-8.el9 · AlmaLinux:9Package registry (OSV)
almalinux:tigervnc-license1.13.1-8.el9 · AlmaLinux:9Package registry (OSV)
almalinux:tigervnc-selinux1.13.1-8.el9 · AlmaLinux:9Package registry (OSV)
almalinux:xorg-x11-server-common1.20.11-24.el9 · AlmaLinux:9Package registry (OSV)
almalinux:xorg-x11-server-devel1.20.11-24.el9 · AlmaLinux:9Package registry (OSV)
almalinux:xorg-x11-server-source1.20.11-24.el9 · AlmaLinux:9Package registry (OSV)
almalinux:xorg-x11-server-Xdmx1.20.11-24.el9 · AlmaLinux:9Package registry (OSV)
almalinux:xorg-x11-server-Xephyr1.20.11-24.el9 · AlmaLinux:9Package registry (OSV)
almalinux:xorg-x11-server-Xnest1.20.11-24.el9 · AlmaLinux:9Package registry (OSV)
almalinux:xorg-x11-server-Xorg1.20.11-24.el9 · AlmaLinux:9Package registry (OSV)
almalinux:xorg-x11-server-Xvfb1.20.11-24.el9 · AlmaLinux:9Package registry (OSV)
debian:xorg-server2:21.1.7-3+deb12u2 · Debian:12Package registry (OSV)
opensuse:xorg-x11-server21.1.4-150500.7.7.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:xwayland23.2.2-1.1 · openSUSE:TumbleweedPackage registry (OSV)
red hat:tigervnc0:1.8.0-26.el7_9 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:tigervnc-debuginfo0:1.8.0-26.el7_9 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:tigervnc-icons0:1.8.0-26.el7_9 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:tigervnc-license0:1.8.0-26.el7_9 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:tigervnc-server0:1.8.0-26.el7_9 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:tigervnc-server-applet0:1.8.0-26.el7_9 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:tigervnc-server-minimal0:1.8.0-26.el7_9 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:tigervnc-server-module0:1.8.0-26.el7_9 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:xorg-x11-server0:1.20.11-24.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:xorg-x11-server-Xdmx0:1.20.11-24.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:xorg-x11-server-Xdmx-debuginfo0:1.20.11-24.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:xorg-x11-server-Xephyr0:1.20.11-24.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
suse:xorg-x11-server1.19.6-10.56.1 · SUSE:Linux Enterprise Software Development Kit 12 SP5Package registry (OSV)
suse:xorg-x11-server21.1.4-150500.7.7.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP5Package registry (OSV)

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.

EPSS, last 120 days

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 researchers

Finders, 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-2022-46343315 days apartA vulnerability was found in X.Org.
    36Monitor
  • CVE-2022-46342315 days apartA vulnerability was found in X.Org.
    35Monitor
  • CVE-2023-1393209 days apartA flaw was found in X.Org Server Overlay Window.
    31Monitor
  • CVE-2023-0494212 days apartA vulnerability was found in X.Org.
    31Monitor
  • CVE-2022-4283315 days apartA vulnerability was found in X.Org.
    31Monitor
  • CVE-2025-26594489 days apartX.org: xwayland: use-after-free of the root cursor
    31Monitor

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.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

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

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

c
free(dev->buf);/* ... another thread is still running ... */process(dev->buf);

Fixed

c
lock(&dev->lock);free(dev->buf);dev->buf = NULL;unlock(&dev->lock);

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

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (17 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records