--- title: "CVE-2025-1012\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-2025-1012?format=md keywords: index, follow --- # CVE-2025-1012 Publication date 6 February 2025 Last updated 26 June 2026 --- Ubuntu priority **Medium** [Why this priority?](https://ubuntu.com/security/cves/about#priority ) ## Cvss 3 Severity Score **9.8 · Critical** [Score breakdown](https://ubuntu.com/security/CVE-2025-1012?format=md#impact-score) Toggle side navigation ## Description A race during concurrent delazification could have led to a use-after-free. This vulnerability was fixed in Firefox 135, Firefox ESR 115.20, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135. [Read the notes from the security team](https://ubuntu.com/security/CVE-2025-1012?format=md#notes) ## Status Show unmaintained releases | Package | Ubuntu Release | Status | | --- | --- | --- | | mozjs52 | 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 | Needs evaluation | | 18.04 LTS bionic | Ignored | | firefox | 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 | Fixed 135.0+build2-0ubuntu0.20.04.1 | | mozjs102 | 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 | Ignored | | 22.04 LTS jammy | Ignored | | 20.04 LTS focal | Not in release | | mozjs115 | 26.04 LTS resolute | Not in release | | 25.10 questing | Not in release | | 25.04 plucky | Ignored | | 24.10 oracular | Ignored | | 24.04 LTS noble | Ignored | | 22.04 LTS jammy | Not in release | | 20.04 LTS focal | Not in release | | mozjs38 | 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 | Needs evaluation | | mozjs68 | 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 | Ignored | | mozjs78 | 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 | Ignored | | 20.04 LTS focal | Not in release | | mozjs91 | 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 | Ignored | | 20.04 LTS focal | Not in release | | thunderbird | 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 | Fixed 1:128.12.0+build1-0ubuntu0.22.04.1 | | 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) ## Notes --- ### [mdeslaur](https://launchpad.net/~mdeslaur) mozjs\* contain a copy of the SpiderMonkey JavaScript engine. It is not feasible to backport security fixes to the mozjs\* packages, as such, marking them as ignored. starting with Ubuntu 22.04, the firefox package is just a script that installs the Firefox snap starting with Ubuntu 24.04, the thunderbird package is just a script that installs the Thunderbird snap ## Severity score breakdown CVSS version: CVSS v3.0 **Base score** 9.8 · Critical * Base metrics | Parameter | Value | | --- | --- | | Attack vector | Network | | Attack complexity | Low | | Privileges required | None | | User interaction | None | | Scope | Unchanged | | Confidentiality impact | High | | Integrity impact | High | | Availability impact | High | * Scores | Parameter | Value | | --- | --- | | Base score | 9.8 · Critical | | Exploitability score | - | | Impact score | - | **Vector:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H ## References * [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-1012) * [NVD](https://nvd.nist.gov/vuln/detail/CVE-2025-1012) * [Launchpad](https://launchpad.net/bugs/cve/CVE-2025-1012) * [Debian](https://security-tracker.debian.org/tracker/CVE-2025-1012) ### Related Ubuntu Security Notices (USN) + [USN-7263-1](https://usn.ubuntu.com/USN-7263-1) + Firefox vulnerabilities + 11 February 2025 + [USN-7663-1](https://usn.ubuntu.com/USN-7663-1) + Thunderbird vulnerabilities + 22 July 2025 ### Other references * * * * * * * * * *