Running servers on Debian 11, Ubuntu 20.04 or CentOS 7? The server audit records versions, risks and the right upgrade path. For organically grown systems without documentation there is the controlled takeover of existing servers.
Every Linux distribution has a fixed end of support. After that date no more security updates are published, not even for critical flaws in the kernel, OpenSSL or OpenSSH. In autumn 2026 this affects many production systems at the same time: Debian 11 has been without security updates from the project since 31 August 2026, Ubuntu 20.04 has only been covered by Ubuntu Pro since May 2025, and Ubuntu 22.04 leaves standard support in May 2027.
This guide collects the dates of the common server distributions from primary sources, explains the terms and compares the three paths after end of support: upgrade, migration and continued operation with paid extended support.
Contents
- Overview: end of support for server distributions
- Terms: EOL, LTS, ESM and ELS
- What happens after end of support
- Three paths: upgrade, migration, continued operation
- Extended support compared
- Procedure in five steps
- Our approach at WZ-IT
- Status and methodology
Overview: end of support for server distributions
The table lists, per version, the end of regular security updates (for RHEL with a subscription) and, where available, the end of paid extended support. Dates with a day come from the projects' release tables; the month values for Ubuntu come from Canonical's overview.
| Version | Regular security updates until | Paid extended support until | Status on 26 Oct 2026 |
|---|---|---|---|
| Debian 10 buster | 30 Jun 2024 (LTS) | 30 Jun 2029 (Freexian ELTS) | no project updates |
| Debian 11 bullseye | 31 Aug 2026 (LTS) | 30 Jun 2031 (Freexian ELTS) | no project updates since September 2026 |
| Debian 12 bookworm | 30 Jun 2028 (LTS, handed to the LTS team on 11 Jul 2026) | 30 Jun 2033 (Freexian ELTS) | supported |
| Debian 13 trixie | 9 Aug 2028 regular, 30 Jun 2030 LTS | 30 Jun 2035 (Freexian ELTS) | current stable release |
| Ubuntu 18.04 LTS | May 2023 | May 2028 (ESM), May 2033 (Legacy) | Ubuntu Pro only |
| Ubuntu 20.04 LTS | May 2025 | May 2030 (ESM), May 2035 (Legacy) | Ubuntu Pro only |
| Ubuntu 22.04 LTS | May 2027 | May 2032 (ESM), May 2037 (Legacy) | supported, ends in about 7 months |
| Ubuntu 24.04 LTS | May 2029 | May 2034 (ESM), May 2039 (Legacy) | supported |
| Ubuntu 26.04 LTS | May 2031 | May 2036 (ESM), May 2041 (Legacy) | supported, current LTS release |
| CentOS Linux 7 | 30 Jun 2024 | no offer from the CentOS project | no updates |
| CentOS Stream 9 | 31 May 2027 | none | supported |
| RHEL 7 | 30 Jun 2024 (end of maintenance) | 31 May 2029 (Red Hat ELS) | ELS only |
| RHEL 8 | 31 May 2029 | 31 May 2033 (ELS per endoflife.date) | supported |
| RHEL 9 | 31 May 2032 | 31 May 2036 (ELS per endoflife.date) | supported |
| AlmaLinux and Rocky Linux 8 | 31 May 2029 | none from the projects | supported |
| AlmaLinux and Rocky Linux 9 | 31 May 2032 | none from the projects | supported |
Sources: Debian Releases, Debian announcement on the end of Debian 11 LTS, Debian Extended LTS, Ubuntu release cycle, Red Hat on CentOS Linux EOL and RHEL 7 ELS, cross-checked against endoflife.date for Debian, Ubuntu, RHEL, AlmaLinux, Rocky Linux and CentOS Stream.
Terms: EOL, LTS, ESM and ELS
The projects name their phases differently. For operations one question matters: until when are security updates available, and who delivers them?
- EOL (end of life): the end of maintenance by the project or vendor. Without an additional contract no further updates are published.
- Debian LTS: Debian maintains every release for five years: three years by the security team, then two years by the LTS team (Debian Releases). LTS is free of charge but only covers selected architectures.
- Debian ELTS: Extended LTS is organised by the company Freexian and funded by paying organisations. Only the subset of packages those organisations need is maintained (Debian Wiki).
- Ubuntu standard support and ESM: every Ubuntu LTS release receives five years of standard security maintenance for the Main repository. Ubuntu Pro extends this with Expanded Security Maintenance (ESM) to ten years for Main and Universe, and the Legacy add-on to 15 years (Ubuntu Pro).
- Red Hat ELS: Extended Life Cycle Support extends RHEL by up to four years with selected critical security fixes for the last minor release, for RHEL 7 that is 7.9 until 31 May 2029 (Red Hat).
What happens after end of support
A server initially keeps running unchanged after the cut-off date. The risk builds up gradually: every newly published flaw in the kernel, system libraries or services stays open permanently. Updating individual packages from third-party sources does not close them, but creates a mixed state that nobody tests any more.
Further effects:
- New software versions require newer libraries. PHP, Python, databases and container runtimes often can no longer be kept current on old base systems.
- Package repositories of old releases move to the archive. Reinstallation and recovery on new hardware become harder.
- Audits and contracts: the German BSI IT-Grundschutz requires in OPS.1.1.3.A15 that unsupported software may only remain in use if an assessment shows it can still be operated securely. If not, it must no longer be used (BSI OPS.1.1.3, edition 2023, German).
End of support also affects applications on the server. One example is PostgreSQL 14, which reaches end of life in November 2026.
Three paths: upgrade, migration, continued operation
| In-place upgrade | Migration to a new system | Continued operation with extended support | |
|---|---|---|---|
| Approach | Raise the distribution on the existing server to the next release | Build a new system on a current release, move services and data | Keep the existing release, obtain security updates from a third party or the vendor |
| Typical cases | Debian 11 to 12, Ubuntu 20.04 to 22.04 | CentOS 7 to AlmaLinux, Rocky Linux or RHEL; heavily grown systems | Specialist software certified only on the old release |
| Risk | Broken configuration, removed packages, reboot required | Overlooked dependencies, parallel operation needed | Only part of the packages covered, costs keep running |
| Result | Full maintenance until the next end of support | Clean new state, often with automation | Time gained, not an end state |
Upgrade: Debian only supports upgrades from the directly preceding release. The Debian 13 release notes state: "Only upgrades from Debian 12 (bookworm) are supported" (Debian release notes). A server on Debian 11 therefore goes to 12 first and then to 13. On Ubuntu the upgrade path runs from LTS to LTS, from 20.04 to 22.04, from there to 24.04 and on to 26.04 (Ubuntu Server docs).
Migration: there is no upgrade within CentOS Linux for CentOS 7. AlmaLinux provides ELevate, a tool based on Leapp that performs in-place upgrades from CentOS 7 to EL8 systems and onwards up to EL10 (AlmaLinux ELevate). Red Hat offers Convert2RHEL for a conversion to RHEL (Red Hat). For heavily grown systems, a rebuild followed by data migration is often easier to plan than a multi-step in-place upgrade.
Continued operation: extended support buys time for a planned upgrade. It does not replace it, because applications and libraries keep ageing.
Extended support compared
| Offer | Applies to | Duration | Price (as of 26 Oct 2026) |
|---|---|---|---|
| Ubuntu Pro (ESM) | Ubuntu 18.04 to 26.04 LTS, Main and Universe (16.04 only with the Legacy add-on until May 2031) | 10 years from release, 15 years with the Legacy add-on | 500 US dollars per server per year (server with unlimited VMs), 25 US dollars per workstation; free for personal use on up to 5 machines; public cloud billed hourly, according to Canonical typically 3 to 4.5% of the compute list price (pricing) |
| Debian Extended LTS (Freexian) | Debian 9, 10, 11; subset of packages | Debian 11 until 30 Jun 2031 | on request; according to the Debian Wiki, Freexian aims to keep updates freely available for individuals and small non-profits (Debian Wiki) |
| Red Hat ELS | RHEL 7.9 (also after converting from CentOS 7) | until 31 May 2029 | through Red Hat or partners; the Red Hat page names no price |
| TuxCare Extended Lifecycle Support | EOL systems such as CentOS 7, according to the vendor over 70 distribution versions | according to the vendor without a fixed end | on request (TuxCare) |
The offers differ in scope. Ubuntu Pro covers the entire archive with ESM, Debian ELTS only the packages needed by the paying organisations, Red Hat ELS selected critical fixes. Before buying, compare the packages actually installed with the vendor's coverage list.
Procedure in five steps
- Record the inventory: distribution, release, kernel, package sources and manually installed software per server.
cat /etc/os-releaseanduname -rprovide the basics; third-party sources are listed under/etc/apt/sources.list.d/or/etc/yum.repos.d/. - Assign dates: every server gets its end of support from the table above. Systems already running without updates move to the top.
- Choose the path: upgrade, migration or time-limited continued operation, depending on application dependencies and the state of the system.
- Protect until the switch: restrict reachable services, review access, confirm backups with a restore test. Guidance is in the Linux server hardening checklist.
- Switch and document: upgrade in a maintenance window, functional test, documentation of the new state and the next end of support. How updates are applied continuously afterwards is described in Linux patch management.
Our approach at WZ-IT
The server audit from 290 euros net one-time records distribution, support status, open risks and the upgrade path per server and delivers a prioritised list of findings. For grown or undocumented systems, the page on the takeover of existing servers describes how we take over legacy setups: an EOL system only keeps running with a documented risk, technical safeguards and an agreed replacement path.
After the switch, Linux server management from 149.90 euros net per server per month continues regular operations: updates in maintenance windows, 24/7 monitoring, backup verification with up to 250 GB of backup storage per server and operational documentation. We manage servers remotely at the existing provider or on-premises. Customers obtain Ubuntu Pro, Freexian ELTS, Red Hat ELS or TuxCare directly from the respective vendor; if it is booked, we integrate the extended support into operations.
Further guides
- Linux server takeover checklist: which information should be available before a change of operator
- Linux server maintenance checklist: lifecycle review as part of regular maintenance
- Linux patch management: process, deadlines and evidence
- Managed vs unmanaged Linux servers: who is responsible for updates
Status and methodology
- Collected: 26 October 2026.
- Dates: from the release tables and announcements of the projects (Debian, Canonical, Red Hat). Cross-checked against the endoflife.date API; for Ubuntu, endoflife.date differs by up to one month in places; Canonical's month values are authoritative. The ELS dates for RHEL 8 and 9 come from endoflife.date.
- Prices: Canonical list prices in US dollars for Ubuntu Pro without a support contract. For Freexian, Red Hat ELS and TuxCare, the linked pages name no prices.
- Not included: SUSE, Windows Server and end-of-support dates of individual applications.
The tables may be reused with attribution and a link to this guide.
Sources
- Debian Releases
- Debian: Debian 11 Long Term Support reaches end-of-life (31 Aug 2026)
- Debian Wiki: LTS/Extended
- Debian 13 release notes: Upgrades from Debian 12
- Ubuntu release cycle
- Ubuntu Pro and Ubuntu Pro pricing
- Ubuntu Server docs: Upgrade your release
- Red Hat: CentOS Linux EOL
- AlmaLinux Wiki: ELevate
- TuxCare Extended Lifecycle Support
- BSI IT-Grundschutz OPS.1.1.3 Patch and change management (edition 2023, German)
- endoflife.date
