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Fencer Vulns
medium 6.1

CVE-2025-49177 json

Xorg-x11-server-xwayland: xorg-x11-server: tigervnc: data leak in xfixes extension's xfixessetclientdisconnectmode

published 2025-06-17 16 mo ago modified 2026-11-04 4 d ago also EUVD-2025-18499

cvss
6.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits
0
none known

Summary

A flaw was found in the XFIXES extension. The XFixesSetClientDisconnectMode handler does not validate the request length, allowing a client to read unintended memory from previous requests.

Patch / fix

  • X.Org xwayland 24.1.7
  • Red Hat Red Hat Enterprise Linux 10 0:24.1.5-4.el10_0
  • Red Hat Red Hat Enterprise Linux 9 0:1.20.11-31.el9_6, 0:23.2.7-4.el9_6
  • Red Hat Red Hat Enterprise Linux 9.4 Extended Update Support 0:22.1.9-6.el9_4
  • xwayland Debian 14 2:24.1.8-1
  • xorg-server Debian 12 2:21.1.7-3+deb12u10
  • xorg-server Debian 14, Debian 13 2:21.1.16-1.2

debian advisories DEBIAN-CVE-2025-49177

  • xwayland Ubuntu 22.04 LTS 2:22.1.1-1ubuntu0.19
  • xwayland Ubuntu 24.04 LTS 2:23.2.6-1ubuntu0.6
  • xwayland Ubuntu 26.04 LTS, Ubuntu 25.10 2:24.1.6-1ubuntu1
  • xorg-server Ubuntu 22.04 LTS 2:21.1.4-2ubuntu1.7~22.04.15
  • xorg-server Ubuntu 24.04 LTS 2:21.1.12-1ubuntu1.4
  • xorg-server Ubuntu 26.04 LTS, Ubuntu 25.10 2:21.1.18-1ubuntu1

ubuntu advisories UBUNTU-CVE-2025-49177

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • xorg-x11-server-Xwayland RHEL 10.0 24.1.5-4.el10_0
  • xorg-x11-server RHEL 9 1.20.11-31.el9_6
  • xorg-x11-server-Xwayland RHEL 9 23.2.7-4.el9_6
  • xorg-x11-server-Xdmx RHEL 9 1.20.11-31.el9_6
  • xorg-x11-server-Xorg RHEL 9 1.20.11-31.el9_6
  • xorg-x11-server-Xvfb RHEL 9 1.20.11-31.el9_6
  • xorg-x11-server-Xnest RHEL 9 1.20.11-31.el9_6
  • xorg-x11-server-common RHEL 9 1.20.11-31.el9_6

red hat advisories RHSA-2025:10258RHSA-2025:9304RHSA-2025:9303

  • xorg-x11-server SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 21.1.15-150700.5.3.1
  • xorg-x11-server SLE Module for Development Tools 15 SP6, SLE Module for Basesystem 15 SP6, openSUSE Leap 15.6 21.1.11-150600.5.12.1
  • xorg-x11-server SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 21.1.4-150500.7.35.1
  • xwayland SLE Workstation Extension 15 SP7 24.1.5-150700.3.3.1
  • xwayland SLE Workstation Extension 15 SP6, openSUSE Leap 15.6 24.1.1-150600.5.12.1

suse advisories SUSE-SU-2025:01981-1SUSE-SU-2025:01980-1SUSE-SU-2025:01979-1SUSE-SU-2025:01975-1SUSE-SU-2025:01974-1

  • xorg-x11-server openSUSE Tumbleweed 21.1.15-6.1
  • xwayland openSUSE Tumbleweed 24.1.8-1.1

opensuse advisories openSUSE-SU-2025:15310-1openSUSE-SU-2025:15311-1

  • xorg-x11-server-Xwayland AlmaLinux 10 24.1.5-4.el10_0

almalinux advisories ALSA-2025:9304

  • xorg-x11-server-Xwayland Rocky Linux 10 24.1.5-4.el10_0

rocky linux advisories RLSA-2025:9304

  • xwayland Alpine 3.24, Alpine 3.23, Alpine 3.22 24.1.7-r0
  • xorg-server Alpine 3.24, Alpine 3.23, Alpine 3.22 21.1.17-r0

alpine advisories ALPINE-CVE-2025-49177

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • xorg-x11-server-Xwayland Azure Linux 3.0 24.1.6-2

azure linux advisories AZL-64271

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-49177 updated cvss 6.1

xorg-x11-server-Xwayland: xorg-x11-server: tigervnc: Data Leak in XFIXES Extension's XFixesSetClientDisconnectMode

  • Red Hat Enterprise Linux 6 tigervnc, tigervnc-server, xorg-x11-server, xorg-x11-server-Xdmx, xorg-x11-server-Xorg, xorg-x11-server-Xvfb, +6 more Red Hat Enterprise Linux 7 tigervnc, tigervnc-icons, tigervnc-server, xorg-x11-server, tigervnc-license, xorg-x11-server-Xdmx, +10 more Red Hat Enterprise Linux 8 tigervnc, tigervnc-icons, tigervnc-server, xorg-x11-server, tigervnc-license, tigervnc-selinux, +11 more Red Hat Enterprise Linux 9 tigervnc, tigervnc-icons, tigervnc-server, tigervnc-license, tigervnc-selinux, tigervnc-server-module, +1 more
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Enterprise Linux AppStream (v. 9) xorg-x11-server 1.20.11-31.el9_6, xorg-x11-server-Xdmx 1.20.11-31.el9_6, xorg-x11-server-Xorg 1.20.11-31.el9_6, xorg-x11-server-Xvfb 1.20.11-31.el9_6, xorg-x11-server-Xnest 1.20.11-31.el9_6, xorg-x11-server-common 1.20.11-31.el9_6, +2 more
    fixed: vendor fix RHSA-2025:9303
  • Red Hat Enterprise Linux AppStream (v. 10) xorg-x11-server-Xwayland 24.1.5-4.el10_0
    fixed: vendor fix RHSA-2025:9304
  • Red Hat Enterprise Linux AppStream EUS (v.9.4) xorg-x11-server-Xwayland 22.1.9-6.el9_4
    fixed: vendor fix RHSA-2025:10258
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) xorg-x11-server-source 1.20.11-31.el9_6, xorg-x11-server-Xwayland 23.2.7-4.el9_6
    fixed: vendor fix RHSA-2025:9303
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) xorg-x11-server-Xwayland-devel 24.1.5-4.el10_0, xorg-x11-server-Xwayland-debuginfo 24.1.5-4.el10_0, xorg-x11-server-Xwayland-debugsource 24.1.5-4.el10_0
    fixed: vendor fix RHSA-2025:9304

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
16 mo ago

Exploit prediction

0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.1 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L

Affected products

  • X.Org xwayland
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Enterprise Linux 9.4 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 8

Classification

Weakness
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.