--- title: "CVE-2025-15366\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-2025-15366?format=md keywords: index, follow --- # CVE-2025-15366 Publication date 20 January 2026 Last updated 19 June 2026 --- Ubuntu priority **Medium** [Why this priority?](https://ubuntu.com/security/cves/about#priority ) Toggle side navigation ## Description The imaplib module, when passed a user-controlled command, can have additional commands injected using newlines. Mitigation rejects commands containing control characters. [Read the notes from the security team](https://ubuntu.com/security/CVE-2025-15366?format=md#notes) ## Status Show unmaintained releases | Package | Ubuntu Release | Status | | --- | --- | --- | | python3.13 | 26.04 LTS resolute | Not in release | | 25.10 questing | Ignored end of life, was ignored [patch breaks RFC conformance] | | 24.04 LTS noble | Not in release | | 22.04 LTS jammy | Not in release | | python3.14 | 26.04 LTS resolute | Not affected | | 25.10 questing | Ignored end of life, was ignored [patch breaks RFC conformance] | | 24.04 LTS noble | Not in release | | 22.04 LTS jammy | Not in release | | python2.7 | 26.04 LTS resolute | Not in release | | 25.10 questing | Not in release | | 24.04 LTS noble | Not in release | | 22.04 LTS jammy | Ignored patch breaks RFC conformance | | 20.04 LTS focal | Ignored patch breaks RFC conformance | | 18.04 LTS bionic | Ignored patch breaks RFC conformance | | 16.04 LTS xenial | Ignored end of ESM support, was ignored [patch breaks RFC conformance] | | 14.04 LTS trusty | Ignored patch breaks RFC conformance | | python3.10 | 26.04 LTS resolute | Not in release | | 25.10 questing | Not in release | | 24.04 LTS noble | Not in release | | 22.04 LTS jammy | Ignored patch breaks RFC conformance | | python3.11 | 26.04 LTS resolute | Not in release | | 25.10 questing | Not in release | | 24.04 LTS noble | Not in release | | 22.04 LTS jammy | Ignored patch breaks RFC conformance | | python3.12 | 26.04 LTS resolute | Not in release | | 25.10 questing | Not in release | | 24.04 LTS noble | Ignored patch breaks RFC conformance | | 22.04 LTS jammy | Not in release | | python3.4 | 26.04 LTS resolute | Not in release | | 25.10 questing | Not in release | | 24.04 LTS noble | Not in release | | 22.04 LTS jammy | Not in release | | 14.04 LTS trusty | Ignored patch breaks RFC conformance | | python3.5 | 26.04 LTS resolute | Not in release | | 25.10 questing | Not in release | | 24.04 LTS noble | Not in release | | 22.04 LTS jammy | Not in release | | 16.04 LTS xenial | Ignored end of ESM support, was ignored [patch breaks RFC conformance] | | 14.04 LTS trusty | Ignored patch breaks RFC conformance | | python3.6 | 26.04 LTS resolute | Not in release | | 25.10 questing | Not in release | | 24.04 LTS noble | Not in release | | 22.04 LTS jammy | Not in release | | 18.04 LTS bionic | Ignored patch breaks RFC conformance | | python3.7 | 26.04 LTS resolute | Not in release | | 25.10 questing | Not in release | | 24.04 LTS noble | Not in release | | 22.04 LTS jammy | Not in release | | 18.04 LTS bionic | Ignored patch breaks RFC conformance | | python3.8 | 26.04 LTS resolute | Not in release | | 25.10 questing | Not in release | | 24.04 LTS noble | Not in release | | 22.04 LTS jammy | Not in release | | 20.04 LTS focal | Ignored patch breaks RFC conformance | | 18.04 LTS bionic | Ignored patch breaks RFC conformance | | python3.9 | 26.04 LTS resolute | Not in release | | 25.10 questing | Not in release | | 24.04 LTS noble | Not in release | | 22.04 LTS jammy | Not in release | | 20.04 LTS focal | Ignored patch breaks RFC conformance | --- * [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 --- ### [vyomydv](https://launchpad.net/~vyomydv) CVE patch breaks conformance with RFC 9051 - Internet Message Access Protocol (IMAP). Initial patch published in USN-8018-1 has been reverted. Python upstream also hasn't backported this patch to the upstream supported releases ## Severity score breakdown CVSS version: CVSS v4.0 **Base score** 5.9 · Medium * Base metrics | Parameter | Value | | --- | --- | | Attack vector | Network | | Attack complexity | Low | | Attack requirements | Present | | Privileges required | High | | User interaction | None | | Vulnerable system - Confidentiality impact | Low | | Vulnerable system - Integrity impact | High | | Vulnerable system - Availability impact | None | | Subsequent system - Confidentiality impact | None | | Subsequent system - Integrity impact | None | | Subsequent system - Availability impact | None | * Scores | Parameter | Value | | --- | --- | | Base score | 5.9 · Medium | | Base + Threat score | - | | Base + Environmental score | - | | Base + Threat + Environmental score | - | **Vector:** CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N ## References * [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-15366) * [NVD](https://nvd.nist.gov/vuln/detail/CVE-2025-15366) * [Launchpad](https://launchpad.net/bugs/cve/CVE-2025-15366) * [Debian](https://security-tracker.debian.org/tracker/CVE-2025-15366) ### Related Ubuntu Security Notices (USN) + [USN-8018-1](https://usn.ubuntu.com/USN-8018-1) + Python vulnerabilities + 5 February 2026 + [USN-8018-2](https://usn.ubuntu.com/USN-8018-2) + Python regression + 9 March 2026 ### Other references * * * * * *