MEDIUM

CVE-2025-49177

CVSS v3

6.1

MEDIUM

EPSS Score

0.4 %

exploit probability, as of 2026-10-19

CISA KEV

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

xorg-x11-server-XwaylandAlmaLinux:10all versions · fixed in 24.1.5-4.el10_0and 1 other package

Vendor advisories

CVE-2025-49177 Red Hat Product Security161 products fixed · 60 known affected
xorg-x11-server-Xwayland: xorg-x11-server: tigervnc: Data Leak in XFIXES Extension's XFixesSetClientDisconnectMode
tigervnc as a component of Red Hat Enterprise Linux 6 · tigervnc-server as a component of Red Hat Enterprise Linux 6 · tigervnc-server-applet as a component of Red Hat Enterprise Linux 6
RHSA-2025:10258 Red Hat Product Security13 products fixed
Red Hat Security Advisory: xorg-x11-server-Xwayland security update
RHSA-2025:9303 Red Hat Product Security123 products fixed
Red Hat Security Advisory: xorg-x11-server and xorg-x11-server-Xwayland security update
RHSA-2025:9304 Red Hat Product Security25 products fixed
Red Hat Security Advisory: xorg-x11-server-Xwayland security update

Full record on NVD

Description

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.

Technical details

CVSS v3 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L
Published: 2025-06-17
Last Modified: 2026-04-15

Frequently asked questions

What is CVE-2025-49177?

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.

Is CVE-2025-49177 actively exploited?

Active exploitation of CVE-2025-49177 has not been confirmed. Its EPSS score was 0.4% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2025-49177?

CVE-2025-49177 has a CVSS v3 base score of 6.1 (MEDIUM severity), with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L.

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