CVE-2025-26595
HIGHCVSS 7.8/10EPSS 0.39%
Last modified
CVE-2025-26595 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. 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. EPSS estimates a 0.39% chance of exploitation in the next 30 days.
Description
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.
Metrics
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Tigervnc | Tigervnc | All versions |
| X.Org | X Server | < 21.1.16 |
| X.Org | Xwayland | < 24.1.6 |
| Redhat | Enterprise Linux | 7.0 |
| Redhat | Enterprise Linux | 8.0 |
| Redhat | Enterprise Linux | 9.0 |
References
- https://access.redhat.com/errata/RHSA-2025:2500Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2502Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2861Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2862Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2865Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2866Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2873Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2874Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2875Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2879Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2880Third Party Advisory
- https://access.redhat.com/security/cve/CVE-2025-26595Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2345257Issue Tracking
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is CVE-2025-26595?
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.
How severe is CVE-2025-26595?
CVE-2025-26595 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.39% probability of exploitation in the next 30 days.
How do I fix CVE-2025-26595?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
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