--- title: "CVE-2025-26596\n | Ubuntu" description: Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things. url: https://ubuntu.com/security/CVE-2025-26596?format=md keywords: index, follow --- # CVE-2025-26596 Publication date 25 February 2025 Last updated 19 August 2025 --- Ubuntu priority **Medium** [Why this priority?](https://ubuntu.com/security/cves/about#priority ) ## Cvss 3 Severity Score **7.8 · High** [Score breakdown](https://ubuntu.com/security/CVE-2025-26596?format=md#impact-score) Toggle side navigation ## Description 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. [Read the notes from the security team](https://ubuntu.com/security/CVE-2025-26596?format=md#notes) ## Status Show unmaintained releases | Package | Ubuntu Release | Status | | --- | --- | --- | | xorg | 26.04 LTS resolute | Not affected | | 25.10 questing | Not affected | | 25.04 plucky | Not affected | | 24.10 oracular | Not affected | | 24.04 LTS noble | Not affected | | 22.04 LTS jammy | Not affected | | 20.04 LTS focal | Not affected | | 18.04 LTS bionic | Not affected | | 16.04 LTS xenial | Not affected | | xorg-hwe-16.04 | 26.04 LTS resolute | Not in release | | 25.10 questing | Not in release | | 25.04 plucky | Not in release | | 24.10 oracular | Not in release | | 24.04 LTS noble | Not in release | | 22.04 LTS jammy | Not in release | | 20.04 LTS focal | Not in release | | 16.04 LTS xenial | Not affected | | xorg-hwe-18.04 | 26.04 LTS resolute | Not in release | | 25.10 questing | Not in release | | 25.04 plucky | Not in release | | 24.10 oracular | Not in release | | 24.04 LTS noble | Not in release | | 22.04 LTS jammy | Not in release | | 20.04 LTS focal | Not in release | | 18.04 LTS bionic | Not affected | | xorg-server | 26.04 LTS resolute | Fixed 2:21.1.16-1ubuntu1 | | 25.10 questing | Fixed 2:21.1.16-1ubuntu1 | | 25.04 plucky | Fixed 2:21.1.16-1ubuntu1 | | 24.10 oracular | Fixed 2:21.1.13-2ubuntu1.2 | | 24.04 LTS noble | Fixed 2:21.1.12-1ubuntu1.2 | | 22.04 LTS jammy | Fixed 2:21.1.4-2ubuntu1.7~22.04.13 | | 20.04 LTS focal | Fixed 2:1.20.13-1ubuntu1~20.04.19 | | 18.04 LTS bionic | Fixed 2:1.19.6-1ubuntu4.15+esm12 Ubuntu Pro | | 16.04 LTS xenial | Fixed 2:1.18.4-0ubuntu0.12+esm17 Ubuntu Pro | | 14.04 LTS trusty | Needs evaluation | | xorg-server-hwe-16.04 | 26.04 LTS resolute | Not in release | | 25.10 questing | Not in release | | 25.04 plucky | Not in release | | 24.10 oracular | Not in release | | 24.04 LTS noble | Not in release | | 22.04 LTS jammy | Not in release | | 20.04 LTS focal | Not in release | | 16.04 LTS xenial | Fixed 2:1.19.6-1ubuntu4.1~16.04.6+esm9 Ubuntu Pro | | xorg-server-hwe-18.04 | 26.04 LTS resolute | Not in release | | 25.10 questing | Not in release | | 25.04 plucky | Not in release | | 24.10 oracular | Not in release | | 24.04 LTS noble | Not in release | | 22.04 LTS jammy | Not in release | | 20.04 LTS focal | Not in release | | 18.04 LTS bionic | Fixed 2:1.20.8-2ubuntu2.2~18.04.11+esm4 Ubuntu Pro | | xwayland | 26.04 LTS resolute | Fixed 2:24.1.5-1ubuntu1 | | 25.10 questing | Fixed 2:24.1.5-1ubuntu1 | | 25.04 plucky | Fixed 2:24.1.5-1ubuntu1 | | 24.10 oracular | Fixed 2:24.1.2-1ubuntu0.4 | | 24.04 LTS noble | Fixed 2:23.2.6-1ubuntu0.4 | | 22.04 LTS jammy | Fixed 2:22.1.1-1ubuntu0.17 | | 20.04 LTS focal | Not in release | --- * [How can I get the fixes?](https://ubuntu.com/security/cves/about#security) * [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses) ### Get expanded security coverage with Ubuntu Pro Reduce your average CVE exposure time from 98 days to 1 day with expanded CVE patching, ten-years security maintenance and optional support for the full stack of open-source applications. 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[Get Ubuntu Pro](https://ubuntu.com/pro) [30-day free trial](https://ubuntu.com/pro/free-trial) ## Notes --- ### [mdeslaur](https://launchpad.net/~mdeslaur) xorg server is actually the xorg-server package the xorg package only contains docs xwayland package contains parts of xorg-server ## Severity score breakdown CVSS version: CVSS v3.0 **Base score** 7.8 · High * Base metrics | Parameter | Value | | --- | --- | | Attack vector | Local | | Attack complexity | Low | | Privileges required | Low | | User interaction | None | | Scope | Unchanged | | Confidentiality impact | High | | Integrity impact | High | | Availability impact | High | * Scores | Parameter | Value | | --- | --- | | Base score | 7.8 · High | | Exploitability score | - | | Impact score | - | **Vector:** CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H ## References * [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-26596) * [NVD](https://nvd.nist.gov/vuln/detail/CVE-2025-26596) * [Launchpad](https://launchpad.net/bugs/cve/CVE-2025-26596) * [Debian](https://security-tracker.debian.org/tracker/CVE-2025-26596) ### Related Ubuntu Security Notices (USN) + [USN-7299-1](https://usn.ubuntu.com/USN-7299-1) + X.Org X Server vulnerabilities + 25 February 2025 + [USN-7299-2](https://usn.ubuntu.com/USN-7299-2) + X.Org X Server vulnerabilities + 10 March 2025 + [USN-7299-4](https://usn.ubuntu.com/USN-7299-4) + X.Org X Server regression + 17 March 2025 ### Other references *