CVE-2025-26595: Xorg: xwayland: buffer overflow in xkbvmodmasktext()
A buffer overflow flaw was found in X.Org and Xwayland. The code in XkbVModMaskText() allocates a fixed-sized buffer on the stack and copies the names of the virtual modifiers to that buffer. The code fails to check the bounds of the buffer and would copy the data regardless of the size.
Other sources
The code in XkbVModMaskText() allocates a fixed sized buffer on the stack and copies the names of the virtual modifiers to that buffer.
The code however fails to check the bounds of the buffer correctly and would copy the data regardless of the size, which may lead to a buffer overflow.
— Red Hat
Xorg: xwayland: buffer overflow in xkbvmodmasktext()
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/xorg-serverto a version that resolves this vulnerability.Fixed in 2:1.20.11-1+deb11u15Fixed in 2:21.1.7-3+deb12u9Fixed in 2:21.1.16-1 - Upgrade
Upgrade
debian/xwaylandto a version that resolves this vulnerability.Fixed in 2:24.1.6-1 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 24.1.6-1 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 1.20.10-15
Event History
Frequently Asked Questions
What is the severity of CVE-2025-26595?
CVE-2025-26595 is classified as a high-severity vulnerability due to the potential for remote code execution resulting from the buffer overflow.
How do I fix CVE-2025-26595?
To mitigate CVE-2025-26595, update to the latest patched versions of xorg-server or xwayland as specified in the vulnerability details.
What systems are affected by CVE-2025-26595?
CVE-2025-26595 affects systems running vulnerable versions of xorg-server and xwayland on Debian distributions.
Is CVE-2025-26595 exploitable remotely?
Yes, CVE-2025-26595 can be remotely exploitable if an attacker can send crafted input to the affected service.
What are the potential impacts of CVE-2025-26595?
The potential impacts of CVE-2025-26595 include system crashes, unauthorized access, and execution of arbitrary code.