#VU104193 Buffer overflow in X.org Server and Xwayland - CVE-2025-26597

Vulnerability identifier: #VU104193

Vulnerability risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-26597

CWE-ID: CWE-119

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
X.org Server
Server applications / Other server solutions
Xwayland
Client/Desktop applications / Multimedia software

Vendor: X.org

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error within the XkbChangeTypesOfKey() function. A local user can trigger memory corruption and execute arbitrary code with elevated privileges.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

X.org Server: 21.0.99.1 - 21.1.15

Xwayland: 21.0.99.901 - 24.1.5

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=2345255
https://gitlab.freedesktop.org/xorg/xserver/-/commit/0e4ed949
https://www.zerodayinitiative.com/advisories/ZDI-25-140/

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.