--- title: "CVE-2025-26601\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-2025-26601?format=md keywords: index, follow --- # CVE-2025-26601 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-2025-26601?format=md#impact-score) Toggle side navigation ## Description A use-after-free flaw was found in X.Org and Xwayland. When changing an alarm, the values of the change mask are evaluated one after the other, changing the trigger values as requested, and eventually, SyncInitTrigger() is called. If one of the changes triggers an error, the function will return early, not adding the new sync object, possibly causing a use-after-free when the alarm eventually triggers. [Read the notes from the security team](https://ubuntu.com/security/CVE-2025-26601?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-2025-26601) * [NVD](https://nvd.nist.gov/vuln/detail/CVE-2025-26601) * [Launchpad](https://launchpad.net/bugs/cve/CVE-2025-26601) * [Debian](https://security-tracker.debian.org/tracker/CVE-2025-26601) ### 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 *