CVE-2025-26594
published 2025-02-25CVE-2025-26594: A use-after-free flaw was found in X.Org and Xwayland. The root cursor is referenced in the X server as a global variable. If a client frees the root cursor…
PriorityP341high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
EPSS
0.36%
28.1th percentile
A use-after-free flaw was found in X.Org and Xwayland. The root cursor is referenced in the X server as a global variable. If a client frees the root cursor, the internal reference points to freed memory and causes a use-after-free.
Affected
20 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | xorg-server | < xorg-server 2:21.1.7-3+deb12u9 (bookworm) | xorg-server 2:21.1.7-3+deb12u9 (bookworm) |
| debian | xwayland | < xorg-server 2:21.1.7-3+deb12u9 (bookworm) | xorg-server 2:21.1.7-3+deb12u9 (bookworm) |
| msrc | azl3_xorg-x11-server-xwayland_24.1.1-3_on_azure_linux_3.0 | — | — |
| msrc | azl3_xorg-x11-server-xwayland_24.1.6-1_on_azure_linux_3.0 | — | — |
| msrc | cbl2_hyperv-daemons_5.15.148.2-1_on_cbl_mariner_2.0 | — | — |
| msrc | cbl2_hyperv-daemons_5.15.153.1-1_on_cbl_mariner_2.0 | — | — |
| msrc | cbl2_xorg-x11-server_1.20.10-15_on_cbl_mariner_2.0 | — | — |
| msrc | cbl_mariner_2.0_arm | — | — |
| msrc | cbl_mariner_2.0_x64 | — | — |
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux | — | — |
| x.org | x_server | < 21.1.16 | 21.1.16 |
| x.org | xorg-server | >= 0 < 2:1.20.11-1+deb11u15 | 2:1.20.11-1+deb11u15 |
| x.org | xorg-server | >= 0 < 2:21.1.7-3+deb12u9 | 2:21.1.7-3+deb12u9 |
| x.org | xorg-server | >= 0 < 2:21.1.16-1 | 2:21.1.16-1 |
| x.org | xorg-server | >= 0 < 2:21.1.16-1 | 2:21.1.16-1 |
| x.org | xwayland | < 24.1.6 | 24.1.6 |
| x.org | xwayland | >= 0 < 2:24.1.6-1 | 2:24.1.6-1 |
| x.org | xwayland | >= 0 < 2:24.1.6-1 | 2:24.1.6-1 |
CVSS provenance
nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
osv7.8HIGH
vendor_debian7.8HIGH
vendor_msrc7.8HIGH
vendor_redhat7.8HIGH
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Ubuntu
X.Org X Server regression
vendor_ubuntu·2025-03-17
CVE-2025-26598 X.Org X Server regression
Title: X.Org X Server regression
Summary: Several security issues were fixed in X.Org X Server.
USN-7299-2 fix vulnerabilities in X.Org X Server. This fix caused
a regression in Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. This update
fix the regression and re-apply the fix for the CVE listed.
We apologize for the inconvenience.
Original advisory details:
Jan-Niklas Sohn discovered that the X.Org X Server incorrectly handled
certain memory operations. An attacker could use these issues to cause the
X Server to crash, leading to a denial of service, or possibly execute
arbitrary code.
Instructions: After a standard system update you need to reboot your computer to make all
the necessary changes.
Ubuntu
X.Org X Server vulnerabilities
vendor_ubuntu·2025-03-10
CVE-2025-26594 X.Org X Server vulnerabilities
Title: X.Org X Server vulnerabilities
Summary: Several security issues were fixed in X.Org X Server.
USN-7299-1 fixed several vulnerabilities in X.Org. This update provides
the corresponding update for Ubuntu 16.04 LTS and Ubuntu 18.04 LTS.
Original advisory details:
Jan-Niklas Sohn discovered that the X.Org X Server incorrectly handled
certain memory operations. An attacker could use these issues to cause the
X Server to crash, leading to a denial of service, or possibly execute
arbitrary code.
Instructions: After a standard system update you need to reboot your computer to make all
the necessary changes.
Red Hat
X.Org: Xwayland: Use-after-free of the root cursor
vendor_redhat·2025-02-25·CVSS 7.8
CVE-2025-26594 [HIGH] CWE-416 X.Org: Xwayland: Use-after-free of the root cursor
X.Org: Xwayland: Use-after-free of the root cursor
A use-after-free flaw was found in X.Org and Xwayland. The root cursor is referenced in the X server as a global variable. If a client frees the root cursor, the internal reference points to freed memory and causes a use-after-free.
A use-after-free flaw was found in X.Org and Xwayland. The root cursor is referenced in the X server as a global variable. If a client frees the root cursor, the internal reference points to freed memory and causes a use-after-free.
Statement: Xorg server does not run with root privileges in Red Hat Enterprise Linux 8 and 9, therefore, Red Hat Enterprise Linux 8 and 9 have been rated with a Moderate severity and are not affected by this bug.
Mitigation: Mitigation for this issue is either not available or t
BSD
OpenBSD 7.5 Errata 018: SECURITY FIX
bsd_advisories·2025-02-25·CVSS 7.8
CVE-2025-26594 [HIGH] OpenBSD 7.5 Errata 018: SECURITY FIX
OpenBSD 7.5 Errata 018: SECURITY FIX
018: SECURITY FIX: February 25, 2025
All architectures Multiple X server issues. CVE-2025-26594 CVE-2025-26595 CVE-2025-26596 CVE-2025-26597 CVE-2025-26598 CVE-2025-26599 CVE-2025-26600 CVE-2025-26601
Ubuntu
X.Org X Server vulnerabilities
vendor_ubuntu·2025-02-25
CVE-2025-26595 X.Org X Server vulnerabilities
Title: X.Org X Server vulnerabilities
Summary: Several security issues were fixed in X.Org X Server.
Jan-Niklas Sohn discovered that the X.Org X Server incorrectly handled
certain memory operations. An attacker could use these issues to cause the
X Server to crash, leading to a denial of service, or possibly execute
arbitrary code.
Instructions: After a standard system update you need to reboot your computer to make all
the necessary changes.
Microsoft
X.org: xwayland: use-after-free of the root cursor
vendor_msrc·2025-02-11·CVSS 7.8
CVE-2025-26594 [HIGH] CWE-416 X.org: xwayland: use-after-free of the root cursor
X.org: xwayland: use-after-free of the root cursor
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.
Mariner: Mariner
redhat: redhat
Customer Action Required: Yes
Remediation: CBL-Mariner Releases
Reference: https://learn.mi
Debian
CVE-2025-26594: xorg-server - A use-after-free flaw was found in X.Org and Xwayland. The root cursor is refere...
vendor_debian·2025·CVSS 7.8
CVE-2025-26594 [HIGH] CVE-2025-26594: xorg-server - A use-after-free flaw was found in X.Org and Xwayland. The root cursor is refere...
A use-after-free flaw was found in X.Org and Xwayland. The root cursor is referenced in the X server as a global variable. If a client frees the root cursor, the internal reference points to freed memory and causes a use-after-free.
Scope: local
bookworm: resolved (fixed in 2:21.1.7-3+deb12u9)
bullseye: resolved (fixed in 2:1.20.11-1+deb11u15)
forky: resolved (fixed in 2:21.1.16-1)
sid: resolved (fixed in 2:21.1.16-1)
trixie: resolved (fixed in 2:21.1.16-1)
Microsoft
ksmbd: validate mech token in session setup
vendor_msrc·2024-02-13·CVSS 7.1
CVE-2024-26594 [HIGH] CWE-125 ksmbd: validate mech token in session setup
ksmbd: validate mech token in session setup
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.
Mariner: Mariner
Linux: Linux
Customer Action Required: Yes
Remediation: CBL-Mariner Releases
Reference: https://learn.microsoft.c
VulDB
Red Hat Enterprise Linux 6/7/8/9 X.org X11 Server/TigerVNC use after free (EUVD-2025-5370 / Nessus ID 216902)
vuldb·2026-06-06·CVSS 7.8
CVE-2025-26594 [HIGH] Red Hat Enterprise Linux 6/7/8/9 X.org X11 Server/TigerVNC use after free (EUVD-2025-5370 / Nessus ID 216902)
A vulnerability described as critical has been identified in Red Hat Enterprise Linux 6/7/8/9. Affected is an unknown function of the component X.org X11 Server/TigerVNC. Executing a manipulation can lead to use after free.
This vulnerability is tracked as CVE-2025-26594. The attack is restricted to local execution. No exploit exists.
GHSA
GHSA-gc32-fmf5-c742: A use-after-free flaw was found in X
ghsa_unreviewed·2025-02-25
CVE-2025-26594 [HIGH] CWE-416 GHSA-gc32-fmf5-c742: A use-after-free flaw was found in X
A use-after-free flaw was found in X.Org and Xwayland. The root cursor is referenced in the X server as a global variable. If a client frees the root cursor, the internal reference points to freed memory and causes a use-after-free.
OSV
CVE-2025-26594: A use-after-free flaw was found in X
osv·2025-02-25·CVSS 7.8
CVE-2025-26594 [HIGH] CVE-2025-26594: A use-after-free flaw was found in X
A use-after-free flaw was found in X.Org and Xwayland. The root cursor is referenced in the X server as a global variable. If a client frees the root cursor, the internal reference points to freed memory and causes a use-after-free.
No detection rules found.
No public exploits indexed.
https://access.redhat.com/errata/RHSA-2025:2500https://access.redhat.com/errata/RHSA-2025:2502https://access.redhat.com/errata/RHSA-2025:2861https://access.redhat.com/errata/RHSA-2025:2862https://access.redhat.com/errata/RHSA-2025:2865https://access.redhat.com/errata/RHSA-2025:2866https://access.redhat.com/errata/RHSA-2025:2873https://access.redhat.com/errata/RHSA-2025:2874https://access.redhat.com/errata/RHSA-2025:2875https://access.redhat.com/errata/RHSA-2025:2879https://access.redhat.com/errata/RHSA-2025:2880https://access.redhat.com/errata/RHSA-2025:3976https://access.redhat.com/errata/RHSA-2025:7163https://access.redhat.com/errata/RHSA-2025:7165https://access.redhat.com/errata/RHSA-2025:7458https://access.redhat.com/security/cve/CVE-2025-26594https://bugzilla.redhat.com/show_bug.cgi?id=2345248https://lists.debian.org/debian-lts-announce/2025/02/msg00036.html
2025-02-25
Published