CVE-2025-26596
published 2025-02-25CVE-2025-26596: 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()…
PriorityP342high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
EPSS
0.40%
32.2th percentile
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.
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_kernel_6.6.57.1-1_on_azure_linux_3.0 | — | — |
| msrc | azl3_kernel_6.6.92.2-1_on_azure_linux_3.0 | — | — |
| 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 | azure_linux_3.0_arm | — | — |
| msrc | azure_linux_3.0_x64 | — | — |
| msrc | cbl2_xorg-x11-server_1.20.10-15_on_cbl_mariner_2.0 | — | — |
| 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.
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.
Red Hat
xorg: xwayland: Heap overflow in XkbWriteKeySyms()
vendor_redhat·2025-02-25·CVSS 7.8
CVE-2025-26596 [HIGH] CWE-787 xorg: xwayland: Heap overflow in XkbWriteKeySyms()
xorg: xwayland: Heap overflow in XkbWriteKeySyms()
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.
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.
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 the currently available options don't meet the Red Hat Produc
Microsoft
Xorg: xwayland: heap overflow in xkbwritekeysyms()
vendor_msrc·2025-02-11·CVSS 7.8
CVE-2025-26596 [HIGH] CWE-787 Xorg: xwayland: heap overflow in xkbwritekeysyms()
Xorg: xwayland: heap overflow in xkbwritekeysyms()
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-2025-26596: xorg-server - A heap overflow flaw was found in X.Org and Xwayland. The computation of the len...
vendor_debian·2025·CVSS 7.8
CVE-2025-26596 [HIGH] CVE-2025-26596: xorg-server - A heap overflow flaw was found in X.Org and Xwayland. The computation of the len...
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.
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
net: dsa: fix netdev_priv() dereference before check on non-DSA netdevice events
vendor_msrc·2024-02-13·CVSS 5.5
CVE-2024-26596 [MEDIUM] net: dsa: fix netdev_priv() dereference before check on non-DSA netdevice events
net: dsa: fix netdev_priv() dereference before check on non-DSA netdevice events
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
VulDB
Red Hat Enterprise Linux 6/7/8/9 X.org X11 Server/TigerVNC XkbSizeKeySyms heap-based overflow (EUVD-2025-5403 / Nessus ID 216902)
vuldb·2026-06-06·CVSS 7.8
CVE-2025-26596 [HIGH] Red Hat Enterprise Linux 6/7/8/9 X.org X11 Server/TigerVNC XkbSizeKeySyms heap-based overflow (EUVD-2025-5403 / Nessus ID 216902)
A vulnerability, which was classified as critical, has been found in Red Hat Enterprise Linux 6/7/8/9. This affects the function XkbSizeKeySyms of the component X.org X11 Server/TigerVNC. This manipulation causes heap-based buffer overflow.
This vulnerability is registered as CVE-2025-26596. The attack needs to be launched locally. No exploit is available.
OSV
CVE-2025-26596: A heap overflow flaw was found in X
osv·2025-02-25·CVSS 7.8
CVE-2025-26596 [HIGH] CVE-2025-26596: A heap overflow flaw was found in X
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.
GHSA
GHSA-c52f-45m8-h2r6: A heap overflow flaw was found in X
ghsa_unreviewed·2025-02-25
CVE-2025-26596 [HIGH] CWE-122 GHSA-c52f-45m8-h2r6: A heap overflow flaw was found in X
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.
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-2025-26596https://bugzilla.redhat.com/show_bug.cgi?id=2345256https://lists.debian.org/debian-lts-announce/2025/02/msg00036.html
2025-02-25
Published