CVE-2025-26597 | Xorg: xwayland: buffer overflow in xkbchangetypesofkey()

A buffer overflow flaw was found in X.Org and Xwayland. If XkbChangeTypesOfKey() is called with a 0 group, it will resize the key symbols table to 0 but leave the key actions unchanged. If the same function is later called with a non-zero value of groups, this will cause a buffer overflow because the key actions are of the wrong size.

Published: 2025-02-25 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2025-26597 is rated Moderate Risk (44.6/100): CVSS High severity, with low exploitation likelihood (EPSS 0.47%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-26597

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.02% 0.47% +0.45%
2 2026-04-05 0.05% 0.02% -0.03%
3 2025-12-22 0.05%

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-26597

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.8 5.9 [email protected]
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.8 5.9 [email protected]

Weakness enumeration for CVE-2025-26597

GitHub Security Advisory for CVE-2025-26597

GHSA-7qjx-378m-p8hm · Severity: high — A buffer overflow flaw was found in X.Org and Xwayland. If XkbChangeTypesOfKey() is called with a...

OS Trackers for CVE-2025-26597

vendor priority summary link
alpine CVE-2025-26597: 2 source package rows (xorg-server, xwayland); 6 state rows across 3 repos (3.21-community, 3.22-community, edge-community); fixed 6, open 0. https://security.alpinelinux.org/vuln/CVE-2025-26597
debian not yet assigned CVE-2025-26597 not yet assigned priority: Debian including 2 source packages (xorg-server, xwayland), 9 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 8, open 1. https://security-tracker.debian.org/tracker/CVE-2025-26597
gentoo high CVE-2025-26597: 1 GLSA(s) (202506-04), 2 atom(s) (x11-base/xorg-server, x11-base/xwayland); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2025-26597
redhat high https://access.redhat.com/security/cve/CVE-2025-26597
suse medium CVE-2025-26597 severity moderate: SUSE including 405 source package names (0.3.2-1.2:libX11-6-1.8.7-150600.3.3.1, 0.3.2-1.2:libX11-data-1.8.7-150600.3.3.1, …), 1071 product×package rows across 215 product lines (Container bci/openjdk, Container bci/openjdk-devel, … (215 product lines)): Fixed 835, Known Affected 231, Known Not Affected 5. https://www.suse.com/security/cve/CVE-2025-26597/
ubuntu medium CVE-2025-26597 medium priority: Ubuntu including 7 source packages (xorg, xorg-hwe-16.04, …), 58 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 25, released 17, not-affected 13, needs-triage 3. https://ubuntu.com/security/CVE-2025-26597

Affected software / configurations for CVE-2025-26597

Vendor Product Version Raw CPE
tigervnc tigervnc cpe:2.3:a:tigervnc:tigervnc:-:*:*:*:*:*:*:*
x.org x_server < 21.1.16 cpe:2.3:a:x.org:x_server:*:*:*:*:*:*:*:*
x.org xwayland < 24.1.6 cpe:2.3:a:x.org:xwayland:*:*:*:*:*:*:*:*
redhat enterprise_linux 7.0 cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
redhat enterprise_linux 9.0 cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*

References for CVE-2025-26597

URL Tags
https://access.redhat.com/errata/RHSA-2025:2500 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:2502 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:2861 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:2862 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:2865 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:2866 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:2873 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:2874 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:2875 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:2879 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:2880 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:3976
https://access.redhat.com/errata/RHSA-2025:7163
https://access.redhat.com/errata/RHSA-2025:7165
https://access.redhat.com/errata/RHSA-2025:7458
https://access.redhat.com/security/cve/CVE-2025-26597 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2345255 Issue Tracking
http://www.openwall.com/lists/oss-security/2026/06/02/1
https://lists.debian.org/debian-lts-announce/2025/02/msg00036.html
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